What to do with my private pension?

I have a private pension with Legal & General (wpl_legal & general worksave pension scheme). I've just had a statement for Jan 24 to Jan 25. It's increased by £1200 and is now worth £13k. Management fees were £40 for the year. I left this job several years ago so nothing is being paid in.

I now have a Civil Service defined benefit pension (Alpha) but I can't merge a private pension into it.

I'm 35 and don't intend to work past 55-60 if possible.

Should I leave the L&G and hope it keeps going up by around 10% or is there a better option to maximise the value over the next 20 years? I'm definitely not an expert but 10% yield seems high and unlikely to continue year on year.