My iPad is barely keeping charge

Start here:

If your iPad won't charge – Apple Support

Charge and monitor the iPad battery - Apple Support

As described your battery may require replacement. Assuming that the iPad remains functional, you would be well advised to directly contact Apple Support - and request a remote battery test. The result of the test may better inform your next steps.

You will find the Contact Support link at top-right of this page. Alternatively, you can open a support case using the excellent Apple Support App. If not already installed on your iPad, the App can be downloaded from the App Store:

https://apps.apple.com/gb/app/apple-support/id1130498044

As a further alternative, you might visit the Genius Bar at your local Apple Store - where the technicians will be able to test and assess you iPad.

Make an appointment at the nearest Apple location to have your iPad evaluated for free.

Once the diagnostics are complete, the staff will explain your options.

Make a Genius Bar Reservation

https://www.apple.com/retail/geniusbar/

Or use the Support app installed on your iPad to start the process.

Apple may be able run some remote diagnostics to help with the problem.