Nothing to indicate on your tax return for the Child Disability Benefit.
From CRA: If you have already applied for the CCB for a child who is eligible for the disability tax credit, the CDB will be calculated automatically for the current and the two previous CCB benefit years. Beyond these benefit years, a written request to the appropriate tax centre or tax services office will have to be submitted.
On your tax return, you may claim a disability amount transfer from your son. Instructions for this transfer are below.
https://turbotax.community.intuit.ca/replies/3293463
