capital gain attachment

Hello, it's my first time doing a self-assessment. I have some capital loss from some investments I've made with an ETF provide (Nutmeg). Can I attach directly the ETF provider annual tax report directly to the capital gain section or do I need to create a new document myself with the same calculations? If so, what does a document like this typically contain? Thanks

Hi,
Any attachments needs to be a PDF. Provided the one from ETF is in that format it will be OK.
Thank you