Purchased used ipad Find My Ipad

Here are the Apple support pages that outline the Activation Lock - and the only mechanisms by which it can be turned off:

https://support.apple.com/en-us/HT201365

https://support.apple.com/en-gb/HT201441

As you will discover, unless you are the owner of the AppleID that was last used to activate the device, or unless you can secure the cooperation of the previous owner, you’ll not be able to defeat or bypass the Activation Lock. Without documentary evidence that you are the original owner (such as sales receipt showing the serial number), Apple won’t assist - and nobody here will be able to help you.

The short answer is you don't. If you don't know the person who locked the iPad, you have purchased a useless device. If the person you bought it from is the person who locked the iPad, they need to remove Activation Lock. You can't remove it. Apple won't remove it. We can't help you remove it.

See these two links. One about Activation Lock --> Turn off Activation Lock - Apple Support

One about buying used devices --> The All Too Common SAD Reality of Buying … - Apple Community

The bottom line is without the direct help of the previous owner whose ID the iPad is locked to, it's a completely useless device to you.