Normally. You just do so.

Remember, that the other process has to commit and pending transactions, that acquired locks on the database - during SQLiteStudio attempt to connect.

how to get a lock when open a dbFile using sqlIteStudio.

sample:
process A open dbFile in python: conn = sqlite3.connect('dbFile?mode=rwc&uri=true&journal_mode=WAL&cache=shared', isolation_level=None)
Process B open the dbFile in SQLiteStudio: how to do?

thanks.

You add database to list of registered databases using "Add database" button in top left corner (or from Database menu). Then you fill in the database dialog. Once you accept it, the database will appear on the databases list in the left-side panel. Double click it and there it is - you're connected.