If you place your images in the static/images directory, and if your baseURL does not include a subdirectory, do this:
https://gohugo.io/getting-started/directory-structure/#directories
static
The static directory contains files that will be copied to the public directory when you build your site.
And it looks like we have answered your question before:
https://discourse.gohugo.io/t/inserting-image-into-post-by-putting-it-under-static-folder-isnt-working/49567/3