Hi there, dannielle.paisle.
According to this information from the HMRC website, there's no definitive answer if a bank statement or a screenshot of it is an acceptable proof of business expense: https://community.hmrc.gov.uk/forums/customerforums/kytr/383d43f7-7dcd-e911-b3b9-00155d9c6b78.
You'll want to gather more evidence such as a picture of the item that you bought in case an audit is conducted. You can also reach out to your accountant for more advice with regards to this matter.
Let me know if you need anything else.
