Refused to execute as script because "X-Content-Type: nosniff" was given and its Content-Type is not a script MIME type

We added an external script in the body tag of our (dev) website https://zonnebeke.reclamebureau-simplify.be/zonnebeke2022/. However, when checking the console, I see the error message:

Refused to execute as script because X-Content-Type: nosniff was given and its Content-Type is not a script MIME type

Any idea if this has to do with Wordpress, or another setting of our website, or how we can solve this issue?

Thanks.