You can pick the Adjustment process when you correct underreported amounts or overreported amounts.
If you owe tax
Pay the amount due by the time you file file Form 941-X
If you have a credit
You overreported employment taxes and want the IRS to apply the credit to Form 941 or Form 944 for the period during which you filed Form 941-X.
The claim process can be used when you’re correcting overreported amounts only and claiming a refund or abatement for the credit.