Have you ever had a UK address through which you can establish a credible credit and financial foot print? if so then you can attempt to start the registration journey to Verify.
Otherwise, your best option is to try to Verify using one of the other certified providers, please see list below:
2. Digidentity (may not require a mobile device)
3. Experian (does not require a mobile device)
4. Post Office (can also Verify EU Citizens)
Alternatively, you can contact the government department direct for the service you require, stating that you were not able to verify online.