Apple music

Hi

I don't use Apple Music very often but now that I am this issue is exploding my brain! please help!

So I want to use certain tracks in social media posts for my work.

I go to iTunes and I find an album that contains a genre of music that I would like to use for various posts. I download it. I then go to a video making app I have and choose to add my iTunes music and all the songs FROM that album I downloaded are there which is great! wooo so far..... However......in order to use a particular song it's now telling me I have to return to iTunes to purchase it before I can use it.

My Q is this: do I have to buy EVERY song on that album in order to use that album at various times when I need it?? if there's 15 songs on the album....well you do the maths! ha! I cannot for the life of me find where I can purchase the album that I downloaded. It only allows me to download and nowhere in the world of Jesus and his wee donkey does it ask me to purchase. SO in my traumatised brain I'm thinking "oh. ok well it allowed me to download and it is THERE on the video app to use...I guess I can use it!?" but no.

What the fudge is going on?!?! I hope that makes sense! I can provide screenshots if more info is needed!!!

Please help!