There are several ways to add a form to a Glow Blogs site.

Jetpack

Jetpack has a contact form module that is very full featured. In Glow Blogs it only works in pages or posts edited with the classic editor.

To add a contact form you need to have activated the Contact Form module in Jetpack, then just click on the Add Contact Form Button, remember to set an email to receive the information.

The Jetpack form has lots of features, different fields radio button & checkboxes. It also will email the results to addresses set in the editor & keep them in your dashboard.

If you are using the block editor to edit pages & posts you need to edit a page or posts in the classic editor to add and edit a jetpack form. You can allow users to switch editors in the Dashboard-> Settings -> Writing.

Other way of gathering feedback.

You can embed Google Forms, links to O365 forms or even via comments.