I apologize for not being clear about how to find the records for Ballyshannon.
The main page for Donegal in the IGP archives is:
Click on 'Church Records'. The main page has a search box but it won't have
updated yet. Maybe it will catch up overnight.
For general Donegal searches - you can also try the Google search engine on the
main IGP Archives page. There are Donegal people mentioned in General Ireland
and in other Counties.
Again - the search engine will be behind on Ballyshannon.