Hi nach,
Firstly you will have to upgrade you hobby ( free plan ) to personal ( paid plan ) on bubble.io to easily able to connect your custom domain with your bubble web app.
Secondly, there is a complete step by step section avaliable in bubble’s manual. Link to the article: Domain & DNS - Bubble Docs.
Everything is explained very clearly.
Hope this helps
Best regards
Priyanshu goyal
Founder at nocodeify.in
i just don’t know how exactly to do these steps with the options my domain registrar gives me.
Who is domain name registrar? Godaddy or namcheap, etc
https://monovm.com/ , i posted pictures of the options it shows me.
Contact your domain registrar support. They will definitely help you. I am not familiar with this dns much. First time heard of it.