Does WordPress block UpdraftPlus migrating website files?

I have Wordfence version 6.3.8 on both a test and live site, along with UpdraftPlus plugin version 2.12.13.1 on both. I am trying to migrate the live site to the test one using UpdraftPlus. I have created a key on the test site, copied this to the live site (basically to give permission) but when I try to send to the test site I get this message:
“Unexpected response: Error: Response from remote site could not be understood (response_not_understood). You should check that the remote site is online, not firewalled, does not have security modules that may be blocking access, has UpdraftPlus version 2.10.3 or later active and that the keys have been entered correctly.”

I have used UpdraftPlus a lot, but am I new to using WordFence. I strongly suspect that Wordfence is blocking this (which I half expected) but I cannot find out how to allow this as an exception. I think it is something I have to add to the whitelist? And if so, how do I figure out what to allow, just for this scenario? I thought I might see something crop up on the Wordfence live traffic of the test site, from which I could click to say, “but this is ok”, but nothing new appears when I try to send this over.