Unable to send MMS from Galaxy note 20 ultra

[Gumi]

So I am looking for any information on getting MMS available, as it is not working on my note 20 ultra. When trying to send a picture, it notifies me that "MMS are not supported by this network". I have tried to use the article from o2 on how to add manual MMS however this has not achieved anything. Any help would be useful!! https://www.o2.co.uk/help/phones-sims-and-devices?page=device/samsung/galaxy-note-20-ultra-5g/topic/...

[Cleoriff]

@Gumi 

Make sure your phone isn't in flight mode. Also mobile data, turn off and back on again.

Reboot the phone and see if that works.

If not reset all network settings.

[Bambino]

@Gumi To add to the good advice from @Cleoriff, if you don't want to waste your data allowance sending MMS, send via WhatsApp or Facebook Messenger which are both free.

[MI5]

MMS are chargeable so won't send if you have a spend cap Guide: Spend caps on O2 

[Bambino]

@Gumi I forgot to add that WhatsApp and Facebook Messenger would be free to use if using them over WiFi.