Go to the activity section > find the MoneyGram transaction that you want to cancel
Then tap on 'more information' and scroll down in the next screen till you find the 'cancel transaction' option.
Note: If you can't see the 'cancel transaction' option you need to email MoneyGram directly to request the cancelation.
Email them to digitalsupport@moneygram.com, add your reference number and stellar wallet address.
💬 You can contact support anytime for more guidance.