Hello, I need help with this one Please,

Need to adjust entries for adjusted trial balance.---in journal form

Year end June 30, 20xx

On June 1, 20xx, Company accepted advance of $21,000 for services to be performed in the next year.

The $21,000 was credited to Unearned Service Revenue.

I have NO ENTRY as my answer.

No services performed in this period so NO adj needed?

Your original transaction would be:
Debit Cash for the amount
Credit Unearned Service Revenue.

If no Service has been provide yet, then there is no adjusting entry.