Hi @Morrile thanks for your post here in the community.
Can you confirm if you live in a 5G based area, and you have a 5G handset - what is the make and model of your handset please?
Generally, 5G SIMs with Oomph are not something that we do and usually these are with our newer plans - I'd advise having a look here to see if there are any suitable plans for you, and you can give our team a call on +44753 301 6422 to discuss plans.
Many thanks
Tom_W