Virtual Work Visa, bank statement needs to be stamped

I applied for the virtual work visa from the UK, and within a minute I got an email back saying my 6 months bank statements need to be stamped? I bank with TSB and they don't do stamps, even in branch. I think this is common for most banks in the UK.

Does anyone know of a workaround for this? The only thing I can think is to take it to a legal notarizer and have them verify it's authenticity and stamp it themselves.