British overseas passport for newborn child - query on supporting documents

Hi all,
We have a new baby born in September 2021. Both parents currently hold British citizenship, acquired through naturalisation but then moved abroad to live in the EU (as British expats, where Baby is born). Having read the guidance, i understand baby is British by birth (as parents can pass their citizenship down one generation) and therefore we have applied for overseas British passport online and have someone confirmed the identity as well.

My question is about the next stage i.e. supporting documents. We have everything they mention on the required list (see below) except Grand Parents birth certificates (highlighted below), as either they dont exist (ie grand parents too old and therefore a birth certificate was never issued for them in their home country or are no longer alive). What is the best course of action in this case? should we send all the other documents with a letter explaining this? Anyone got any experience similar to this, would be grateful for your help / guidance.


Applicant’s documents
Send the following:

full birth (civil and hospital) or adoption certificate showing both the child’s and parents’ details

For 1 of your parents, send 1 of the following:
full birth or adoption certificate (showing both the child’s and parents’ details)
naturalisation or registration certificate

Grandparents’ documents
Send all of the following for both maternal grandparents:

full birth or adoption certificate
grandfather’s marriage certificate to your grandmother (if this applies)
And all of the following for both paternal grandparents:

full birth or adoption certificate
grandfather’s marriage certificate to your grandmother (if this applies)

Child is British through you being British - not through the grandparents - note (if this applies).
So child (who is the applicant) provides:
For 1 of your parents, send 1 of the following:
full birth or adoption certificate (showing both the child’s and parents’ details)
naturalisation or registration certificate

Thanks. Relieved to hear that!