UK Freelancer working for four months in a Spanish Company

Hello,

I am currently unemployed in the UK since last February due the pandemic. I have been offered a four months Interior design contract as freelancer in Spain, would it be possible to become a freelance in the UK and work for them? where would I pay taxes? What the Spanish company would have to do?

Thank you very much, I am really lost in this subject.

Raquel Camino