Gap year at 17

I want to take a gap year and do volunteering but I am struggling to find volunteer opportunities in Scotland or the rest of the UK that would last a year and accept 17 year olds.

I have found some abroad such as latitude but I am unsure if there are safe.

I heard someone once went abroad with the princes trust although I cannot find information of this on the website.

I know the Smiles Foundation and The Vine Trust often do volunteering trips for teens but not sure if they do year long trips. I'm going to Romania with Smiles in June so i know its decent. Dunno if this helps.