adding BTEC course in UCAS

Hi, I'm currently on a gap year and am applying for 2021 so I already have my A level and BTEC qualifications and am trying to add these into UCAS. My question is, for my BTEC (creative media production) there's an option to add modules. All the units I did in my course are included on the certificate, do I need to add the details for this? Has anyone here applied on UCAS with BTECS and can give me an answer?

I've looked on that website now, there are multiple numbers/characters at the bottom of my certificate, how do I know which one it is?

It’s the 7 digit number/letter string at the bottom of the first page of your certificate