Internet Recovery Mode (error message -2100F)

I came across this error message after upgrading the SSD in my MacBook Air 11-inch (Early 2015) that I just bought secondhand on eBay and found two threads in communities with people encountering the same issue after doing a Google search.

I believe that the error message has to do with the computer not being able to find an internet connection because after shutting down the machine and restarting with the same "option + command + R" keys, after a few minutes, I successfully got the dialog to "choose a network" and from there, everything was smooth sailing (it went to the MacOS Big Sur installations screen).

Hope this information helps!

(So, if you come across this same error message on your Mac, for whatever reason, just shut down and restart again in Internet Recovery mode and see if that works).