Straight from the documentation:
Requiring a Value for a Field
lightning-input-field supports requiredness specified on the server and
client. In record forms, a required field is displayed with a red
asterisk next to the field label. If you interact with a required
field but don't enter a value, an error message is displayed below the
field. Similarly, if ...
And the it becomes ...
It is possible to get records "without apex" or without using the lwc wrappers that leverage the uiRecordApi. If you go through the User Interface API Developer Guide, you can find sample apps (external) and detailed methods and endpoints that can be used to interact with the DB.
There are several things that need to be considered to make this work:...
Try to change
If that worked, your problem was that ...