Position Restraining CNT during MD Production

GROMACS version: 2020.4
GROMACS modification: No
Hi,
I want to position restrain the CNT during production. I have encountered following error

Cannot find position restraint file restraint.gro (option -r). From gromacs-2018, you need to specify the position restraint coordinate files explicitly to avoid mistakes, although you can still use the same file as you specify for the -c option.

As far my understanding the position restraint file is generated in ,itp format. I have included and used the same in NVT and NPT equillibration. How can go about it?

Do I need to generate restraint.gro? If so then How?

Can I include the restraint.itp through -r?

I’m attaching my topology file and md.mdp file herewith
topol.top (375.2 KB)
md.mdp (2.8 KB)