Hi I am due to travel to Mojacar in may I am not boosted can I still travel if I do a private lateral flow tests - Page 2

No problems if you have Residencia just complete the Spanish locator form 

Have seen this on N332 page, may be of help: Update to entry requirements for visitors to Spain from the UK*

If you are coming to visit Spain from the UK, there has been a change to the documentation you need to provide. If you have a digital COVID certificate, you no longer need to complete Spain's travel health form. Children under 12 do not need to complete the travel health form either. 

Other requirements remain in place. If you are travelling to Spain for tourism, you must show proof of either:

- being fully vaccinated (with both doses of a 2-dose vaccine or one dose of a single-dose vaccine). Your final dose must have been administered within 270 days prior to travel to Spain or you must be able to show evidence of having had a booster jab

- having recovered from COVID-19 within the last six months

For further detail see https://www.gov.uk/foreign-travel-advice/spain/entry-requirements