Any tips on best nocode/lowcode backend database as a service for web/mobile apps?

Hi IHs!

This is my 1st post since joining some weeks ago and posting an introduction.
Overall, I think this is a great community.

To my question. I am trying to use no code tools to build some web apps and hopefully a few mobile apps. I initially started with Bubble because it was easy to use and the apps are hosted for you. However, I ran into issues making my app responsive on a smart phone and started looking for other alternatives. I am currently oscillating between using UI Bakery (which appears to create great UIs but still early stage with regards connectivity to and usage of data) and Appgyver (which has been around for a while and seems to have great connectivity and usage of data but I am having issues with easily creating a nice UI). For either of these two options, I need a backend database with exposed REST APIs that I could use.

I am currently using Backendless with UI Bakery, but I am having a hard time using the drag and drop logic builder in Backendless to create APIs. On the face of it, it looks intuitive using drag and drop blocks to create your query or logic, but it gets pretty confusing with a huge amount of blocks and trying to figure out the right one to do what you want. With all that said and my above frustrated mini rant regarding the above no code tools, DOES ANYONE HAVE RECOMMENDATIONS FOR OTHER NOCODE/LOWCODE BACKEND DATABASE PLATFORMS THAT COULD BE USED TO STORE DATA AND CREATE REST APIs TO USE ON NOCODE APP BUILDERS? I would appreciate any tips anyone can provide.

FYI - I know SQL, so a platform that allows me to create my own sql queries or stored procedures and expose them via a REST API would also work great. With such a tool, I could perhaps look into a managed DB (on AWS?) and then use such a tool to create and expose REST APIs to my database's stored procedures.

Pardon the long text above and I look forward to any suggestions! Have a great day everyone.