Can't use The SGD optimizer

I am using the following code:

from tensorflow.keras.regularizers import l2
from tensorflow.keras.models import Sequential
from tensorflow.keras.layers import Add, Conv2D, MaxPooling2D, Dropout, Flatten, Dense, BatchNormalization, Activation
from tensorflow.keras import activations

CNN_model = Sequential()
# The First Block
CNN_model.add(Conv2D(128, kernel_size=2,kernel_initializer='he_uniform', kernel_regularizer=l2(0.0005), padding='same', input_shape=(700, 460, 3)))
CNN_model.add(Activation(activations.relu))
CNN_model.add(BatchNormalization())
CNN_model.add(MaxPooling2D(2, 2))


# The Second Block
CNN_model.add(Conv2D(128, kernel_size=2, kernel_initializer='he_uniform', kernel_regularizer=l2(0.0005), padding='same'))
CNN_model.add(Activation(activations.relu))
CNN_model.add(BatchNormalization())
CNN_model.add(MaxPooling2D(2, 2))

# The Third Block
CNN_model.add(Conv2D(128, kernel_size=2, kernel_initializer='he_uniform', kernel_regularizer=l2(0.0005), padding='same'))
CNN_model.add(Activation(activations.relu))
CNN_model.add(BatchNormalization())
CNN_model.add(MaxPooling2D(2, 2))

# The fourth Block
CNN_model.add(Conv2D(128, kernel_size=2, kernel_initializer='he_uniform', kernel_regularizer=l2(0.0005), padding='same'))
CNN_model.add(Activation(activations.relu))
CNN_model.add(BatchNormalization())
CNN_model.add(MaxPooling2D(2, 2))

# The fifth Block
CNN_model.add(Conv2D(128, kernel_size=2, kernel_initializer='he_uniform', kernel_regularizer=l2(0.0005), padding='same'))
CNN_model.add(Activation(activations.relu))
CNN_model.add(BatchNormalization())
CNN_model.add(MaxPooling2D(2, 2))
rom tensorflow.python.keras.engine.training import Model 
from tensorflow.keras import backend as K, regularizers
from tensorflow.keras import losses
CNN_model.add(Flatten()) 
# Layer 1
CNN_model.add(Dense(800,activation='relu',kernel_regularizer=l2(0.0005))) 
CNN_model.add(Dropout(0.5))
# Layer 2
#CNN_model.add(Dense(25, activation='relu',kernel_regularizer=l2(0.0005))) 
#CNN_model.add(Dropout(0.5))

# Layer 5
CNN_model.add(Dense(8, activation='softmax')) 
from tensorflow.keras.optimizers import SGD
opt=SGD(learning_rate=0.1, momentum=0.2, nesterov=True)
CNN_model.compile(SGD, loss = 'categorical_crossentropy', metrics = ['acc'])

However, I get the following error:

ValueError                                Traceback (most recent call last)
ipython-input-9-a5e98777f528 in module
      1 from tensorflow.keras.optimizers import SGD
      2 opt=SGD(learning_rate=0.1, momentum=0.2, nesterov=True)
---- 3 CNN_model.compile(SGD, loss = 'categorical_crossentropy', metrics = ['acc'])

~\anaconda3\lib\site-packages\tensorflow\python\keras\engine\training.py in compile(self, optimizer, loss, metrics, loss_weights, weighted_metrics, run_eagerly, steps_per_execution, **kwargs)
    566       self._run_eagerly = run_eagerly
    567 
-- 568       self.optimizer = self._get_optimizer(optimizer)
    569       self.compiled_loss = compile_utils.LossesContainer(
    570           loss, loss_weights, output_names=self.output_names)

~\anaconda3\lib\site-packages\tensorflow\python\keras\engine\training.py in _get_optimizer(self, optimizer)
    604       return opt
    605 
-- 606     return nest.map_structure(_get_single_optimizer, optimizer)
    607 
    608   @trackable.no_automatic_dependency_tracking

~\anaconda3\lib\site-packages\tensorflow\python\util\nest.py in map_structure(func, *structure, **kwargs)
    865 
    866   return pack_sequence_as(
-- 867       structure[0], [func(*x) for x in entries],
    868       expand_composites=expand_composites)
    869 

~\anaconda3\lib\site-packages\tensorflow\python\util\nest.py in listcomp(.0)
    865 
    866   return pack_sequence_as(
-- 867       structure[0], [func(*x) for x in entries],
    868       expand_composites=expand_composites)
    869 

~\anaconda3\lib\site-packages\tensorflow\python\keras\engine\training.py in _get_single_optimizer(opt)
    595 
    596     def _get_single_optimizer(opt):
-- 597       opt = optimizers.get(opt)
    598       if (loss_scale is not None and
    599           not isinstance(opt, lso.LossScaleOptimizer)):

~\anaconda3\lib\site-packages\tensorflow\python\keras\optimizers.py in get(identifier)
    129     return deserialize(config)
    130   else:
-- 131     raise ValueError(
    132         'Could not interpret optimizer identifier: {}'.format(identifier))

ValueError: Could not interpret optimizer identifier: class 'tensorflow.python.keras.optimizer_v2.gradient_descent.SGD'

I am not mixing keras with tensorflow.keras, so why am I getting this error?