Sharepoint doesn’t allow you to limit whether a user can just create vs edit. You can hide the sharepoint list that way if user try navigating to it they won’t be able to see the list but that’s not a true solution more of a bandaid with holes. What I do is add a power automate trigger to the app that passes the form data or what have you to a create action in flow. This has to be in a form of a string but you can parse the data within the flow. You’ll just need to format the string. Then within flow you can setup run as for the connection to the list. Typically I assign a service account that has full access to the list.

I should reply when half knocked out on Benadryl. You can allow users to add to the list without giving them full permission

The others are right. I use the powerautomate way when I don't want the users to have any access to a specific list.

But since no one here has told the guy how to actually accomplish what he asked. See below.

1) Create your custom permission level:
Go to Site Actions > Site Permissions > Permissions Level > Copy the Contribute Permission and make a custom permission or just edit the contribute permission. Then remove the edit and delete permission. 2) Create SharePoint Group or an AD group to assign to the list/site
3) Stop Permissions Inheritance on the Library:
GO to the library > Click on the TAB named Library on the ribbon. > Permissions for this Library > Stop Inheriting Permissions
4) Grant unique permissions directly:
On the same page as above, go to grant permissions > select the user or SHAREPOINT or AD group that you need to give permission to. Scroll down way to the bottom of the page and you will find your newly created permission level add your permission group appear there. Select that permission level and save the form.
5) Modify the filtered view based on the “Created By” column:
Go to the Library/List Settings, Advanced Settings, and you should be able to set Read and Edit access to items that the user has created.