Decoder installation

Hello,

I changed my internet/TV/phone provider (now SFR).

This morning, the technician came, connected the box, and left without actually saying he was leaving (a water trough thrown from the driveway and by the time I started thinking about what he told me, he was already gone...).

He therefore did not install the TV decoder. I took care of it myself (with the agreement of SFR, who called me to ask if I was satisfied with his intervention).

The problem is that once everything is properly connected, I get this message on the TV that I need to press a button to get started. But where should I press?

On the new remote control? But it isn't paired with the decoder yet, so it's not working.

On the TV remote? That doesn't work either...

I'm sure I'm missing essential information, but I can't see what it is.

Thank you in advance for your help.