Re instating my old Orange number.

I had an Orange number
00 216 55 277 799
that i didn't use for maybe 2 years.
I need to get the number back upon my arrival toTunis on 6 November 2026.
Number is still not sold and seems it is still available.
So what are the steps to re buy it again?
Thanks
Khalil Lababidi
Passport P402515PC (Canadian)