I have a second hand ipad but it's locked for 5 years, i Don't know what to do please help me,model A1455,FCC ID BCGA1455 IC 579C A1455,SERIAL DLXL10PEF19M

the activation lock is not really on

the ipad it's a theft protection measure on apples servers

it needs to be removed

How to remove Activation Lock - Apple Support

if you don't know your appleID

Recover Your Apple ID - Apple

if that does not help you then you

need the assistance of apple

Additional Support - Activation Lock (apple.com) and or

Get Support (apple.com) , Genius Bar Reservation and Apple Support Options - Apple

As is, the iPad is useless to you.

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

Activation Lock for iPhone, iPad, and iPod touch - Apple Support

Turn off Activation Lock – Apple Support

As you will discover, unless you are the owner of the AppleID that was last used to activate the device, you’ll not be able to defeat or bypass the Activation Lock. With documentary evidence that you are the original owner (such as sales receipt showing the serial number), Apple may be prepared to assist - otherwise they and nobody here will be able to help you.

The All Too Common SAD Reality of Buying … - Apple Community

That device (an iPad 4th generation, firstly released in 2012), suffers from Activation Lock (an anti-theft measure).

Neither we, just users like you, nor Apple can help you, sorry, unless you are the original owner and you still have the proof of purchase (receipt/invoice reporting your device’s IMEI or Serial Number). Should be this case, start your request using this link: https://al-support.apple.com/#/additional-support

Shouldn’t be this case, activation lock can be removed only by the previous owner, with the credentials that were used to activate that iPhone/iPad. Without those credentials, that device is useless to you.

Read also this support article:--> How to remove Activation Lock - Apple Support

Regards

Giulio