RoA application and biometric appointment for 10 months old child

[vab]

Hello experts

I have received an email today morning as a reminder to book a biometric appointment within 30 days.
The application I made was for my 10 months old son who was 6 months old at the time of application. Details are as follows

DATE OF APPLICATION: 10 April 2021
TYPE OF VISA / APPLICATION: Right of abode (ROA)

After submitting the application I was not asked to book any appointment as next steps and also it was not mentioned in the document checklist.
According to the checklist documents only two photographs were required to send along with his passport and other mandatory documents.
The reminder letter is asking me to return to my online application to book and attend an appointment at a UK Visas and Citizenship Application Service point to enrol biometrics (fingerprints, facial photograph, signature). However, there is no such option to do so when I log in to account.
I have contacted UKVI they say contact UKVCAS when I contact UKVCAS they are saying contact UKVI.
Please advise me what to do next.

Should I consider this as general reminder or home office has started to enrol biometric for 10 months old child.

TIA
Vab

[vab]

Any suggestions? I am really worrying about this. There is no proper respose from both ukvi and ukvcas. I have 30 days to book appointment but i can not see any option in my ukvi online account.