Not a lot to go on. 'Abroad' is a big place
Some things to try:Check data roaming is on in phone settings
Manually search for another network
Turn off 5g
Change your data APN to "mobile.o2.co.uk" (not PAYG)
Check with O2 whether you have a roaming bar on your account.
Do this via social media If you message O2 on Facebook ( https://o2uk.co/O2CFB) , Twitter ( https://o2uk.co/O2CTW) or Instagram ( https://o2uk.co/O2CIG) , they should be able to help
This is not O2 and we are all customers here similar to yourself and cannot answer account type queries.
