The AGI is an amount. It could be any length. Are you trying to enter it in the PIN #? You enter the AGI on one of the very last steps before you file. Can you post a screen shot of where you are trying to enter it?
Where to enter or correct the prior year AGI
https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/correct-2020-agi-turbotax-onl...
