how to enable jdtls postfix completion in neovim?

[bobolele]

This is my profile

local config = {
    cmd = {
       "java",
       "-Declipse.application=org.eclipse.jdt.ls.core.id1",
       "-Dosgi.bundles.defaultStartLevel=4",
       "-Declipse.product=org.eclipse.jdt.ls.core.product",
       "-Dlog.protocol=true",
       "-Dlog.level=ALL",
       "-Xms1g",
       "--add-modules=ALL-SYSTEM",
       "--add-opens",
       "java.base/java.util=ALL-UNNAMED",
       "--add-opens",
       "java.base/java.lang=ALL-UNNAMED",
       "-javaagent:~/Lsp/jdt-lsp/plugins/lombok.jar",
       --        "-Xbootclasspath/a:~/Lsp/jdt-lsp/plugins/lombok.jar",
       "-jar",
       "~/Lsp/jdt-lsp/plugins/org.eclipse.equinox.launcher_1.6.400.v20210924-0641.jar",
       "-configuration",
       "~/Lsp/jdt-lsp/config_mac",
       "-data",
       "~/Lsp/jdt-lsp/workspace/folder"
    },
    root_dir = require("jdtls.setup").find_root({".git", "mvnw", "gradlew"}),
    settings = {
        java = {
            completion = {
              postfix = {
                enabled = true   /// it does not work.
              }
            },
            configuration = {
            },
        }
    },
    init_options = {
        bundles = {}
    },
    on_attach = function(client, bufnr) 
        require'jdtls.setup'.add_commands()
    end
}

require('jdtls').start_or_attach(config)

my jdtls verison is : 1.20

I solved this problem by adding configurations

local capabilities = vim.lsp.protocol.make_client_capabilities()
capabilities.textDocument.completion.completionItem.snippetSupport = true

local config = {
    capabilities = capabilities,
    .......
}