If I wasn't using web applications, I'd ask them to bring evidence with them at interview. If you're interviewing online at the moment, I'd ask them to send it to you when confirming the interview time.

I also found this link which might be helpful just now;
www.gov.uk/.../coronavirus-covid-19-right-to-work-checks

I ask to bring to interview usually.

We also ask to provide at interview and as a last resort will check on their first day but it must be done first thing before they start work.

In reply to Stacey:

We also check at interview (we have a method to do this remotely just now) and follow up before or not later than 9.30 a.m. on first day if the individual w have appointed has been sponsored as they will have obtained their visa between appointment and start. We are also aware that the Home Office has indicated that we should be following up the remote checks with an in person check once we are back working F2F but given this has gone on for so long I really hope we won't have to do that as we have continued to recruit - and sponsor - throughout lockdown.
Prior to lockdown we always made it clear that if the check had not been carried out by 9.30 on first day, the contract could not start and they could not be paid until then. We have had fewer instances in lockdown as we have been able to do the checks via Zoom or Skype.

Thank you all so much for your replies! Much appreciated!