OIC [Cloud SaaS] - can we create OIC instance under custom domain ?

Hi Experts,

Need an advise in the view of best practise in setting-up OIC instance,

is that possible to launch OIC instance under custom IAM domain ?

I've created OIC instance under compartmentA, OIC service launched by default under "Default Domain". Is it only the way when we launch PaaS services or is that possible to move to required custom IAM domain. pls advise.

Below is best practise document referring:

Thanks,