Unable to get ios13 updates

On Settings, go to General, then Software Updates. There, you should be able to update your iPad to the latest version. However, if it does not seem to show up, your iPad might be too old for the update.

https://support.apple.com/guide/ipad/update-ipados-ipad9a74c576/13.0/ipados/13.0

A little hard to help/advise you when you provide NO information about your iPad.

Here are my questions to you.

Can you, please, confirm what year and model iPad do you have/own?

The “A” model number can be found on the aluminium back of your iPad, in very small print, right under the larger bold print “iPad” on the back of the iPad.

What iOS/iPadOS version is this iPad, currently, running?

What is the rated, internal data storage space/capacity of your iPad model and how much of this free, internal data storage capacity is left inside of your iPad model?

All of that additional info can be found in the Settings app, General settings panel, About.

Please try to attempt to answer all questions asked.

Thank You.