I have a gunite pool with ideal tile coping.
I opted to have a local masonry man do the deck installation with pavers.
According to the leaflet the pool builder left me it states to use an expansion joint and tar. I have called the pool builder but have not yet heard a word on how the expansion foam is installed by their standards.

What I understand is the expansion material is applied to the back of the coping and then a paver in laid. After installation the top of the expansion foam peels off where one then lays a sealant
They state to apply tar to the coping, gunite and joint .
Is the tar acting as an adhesive? Or a sealant?how far does the tar need to go? The length of the coping or further?
How does the expansion foam stay in place? Is one to nail it to the coping?
I guess what I am asking is how does one install the expansion foam the correct way.
Can I use mastic as an adhesive?
Can you scatter the paver grout sand into the silex sealant?

I have already tried googling my questions but am still confused on how foam application is done.