As stated in the Glossary, Enable NFT, Send and Add Coin are considered as transactions. And the Reject Transaction sequence is the exactly the same. Therefore, we will show just one set of screenshots to demonstrate how to reject a transaction.
In this particular example, the proposer first proposed to send some APT out, then changed their mind to reject.
Note, when the proposer changes from approve to reject, the transaction does not automatically cancel itself. Since the threshold set for this account, there needs to be another vote to reject.
This co-manager chooses to reject as well.