Check https://learn.microsoft.com/en-us/sql/relational-databases/lesson-2-connecting-from-another-computer?view=sql-server-ver16

>
>The situation:
>SQL Server (SQLEXPRESS) is installed on a PC (not server). Everything works on this PC.
>Another desktop is connected to the PC (above). I can open all folders on the PC from the remote desktop; no problem.
>But when application attempts to connect to the SQLEXPRESS, there is an error.
>Errors:
>SQL Server Error: 17
>SQL State: 01000
>
>Does the SQL Browser and/or Agent have to run on the PC where SQLEXPRESS is installed?
>
>Any other suggestions?
>
>TIA