Could you add compatibility with beltlayer mod?, I asked therax to add the compatibility, but he told me it has to be done on your end

With this one? https://mods.factorio.com/mod/Layerd-Belts
Yes, it's pretty simple.

Nope, this one
https://mods.factorio.com/mod/beltlayer

Added!

    {type = 'transport-belt', name = 'beltlayer-bpproxy-transport-belt', tier = 2},
    {type = 'transport-belt', name = 'beltlayer-bpproxy-fast-transport-belt', tier = 3},
    {type = 'transport-belt', name = 'beltlayer-bpproxy-express-transport-belt', tier = 4},
    {type = 'transport-belt', name = 'beltlayer-bpproxy-basic-transport-belt', tier = 1},
    {type = 'transport-belt', name = 'beltlayer-bpproxy-turbo-transport-belt', tier = 5},
    {type = 'transport-belt', name = 'beltlayer-bpproxy-ultimate-transport-belt', tier = 6},
    {type = 'underground-belt', name = 'beltlayer-bpproxy-underground-belt', tier = 2},
    {type = 'underground-belt', name = 'beltlayer-bpproxy-fast-underground-belt', tier = 3},
    {type = 'underground-belt', name = 'beltlayer-bpproxy-express-underground-belt', tier = 4},
    {type = 'underground-belt', name = 'beltlayer-bpproxy-basic-underground-belt', tier = 1},
    {type = 'underground-belt', name = 'beltlayer-bpproxy-turbo-underground-belt', tier = 5},
    {type = 'underground-belt', name = 'beltlayer-bpproxy-ultimate-underground-belt', tier = 6},
    {type = 'loader', name = 'underground-belt-beltlayer-connector', tier = 2},
    {type = 'loader', name = 'fast-underground-belt-beltlayer-connector', tier = 3},
    {type = 'loader', name = 'express-underground-belt-beltlayer-connector', tier = 4},
    {type = 'loader', name = 'basic-underground-belt-beltlayer-connector', tier = 1},
    {type = 'loader', name = 'turbo-underground-belt-beltlayer-connector', tier = 5},
    {type = 'loader', name = 'ultimate-underground-belt-beltlayer-connector', tier = 6},