Conditional inclusion of autocomplete sources

[youneedmorethinking]

I have a problem. I need the autocomplete to exclude the "buffer" source when there is an active lsp in the buffer, but I don't know how to do it. Here is the part of my config related to sources:

sources = cmp.config.sources({
        { name = "path" },
        { name = "nvim_lsp" },
        { name = "nvim_lsp_signature_help" },
        {
            name = "buffer",
            option = {
                keyword_length = 2,
            },
        },
}),

Thanks in advance.