Bootstrap 4 Theme Post Layout

I am using Bootstrap 4 Theme in WordPress. I have moderate experience in customizing themes. The text in my Posts is left aligned within the row (appearing on the edge of the container or the web page itself). I would like the text to appear down the center of the web page. Can I centre-align the text using Custom CSS? Thanks

When I inspect the code relating to the column, it appears as follows:

.col-lg-8 {
-webkit-box-flex: 0;
-ms-flex: 0 0 66.6666666667%;
flex: 0 0 66.6666666667%;
max-width: 66.6666666667%;
}