Problems connecting WPS

Hi, I am trying to connect HP M2020 printer with WPS to RB951G-2HnD router os 6.47.3.
I get message: failed, not using push-buttong method in M1 (see attached file).

I could not find this error message in the manual or forum.
Any idea what is the meaning of this message?
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With a printer a few years back…
I couldn’t get it to connect to WPS.

Made an unencrypted network and connected the printer is o that. Then I used the web GUI of the printer to enter the SSID and password for the actual network. Hit apply and the printer has been on wireless for several years now.