error log backwp up

Hello,

for a week I can’t make a backup, an error always comes up and I don’t understand what it is. I removed my dropbox identification and I put it back, one day it worked, but now it doesn’t work at all….

Here is a screenshot of the problem: https://www.dropbox.com/s/afqved3m7opaicy/Capture%20d%E2%80%99%C3%A9cran%202023-02-27%20%C3%A0%2013.11.39.png?dl=0