Trigger Luasnips with hotkeys / programatically?

1

I have this in my init.lua, I looked up how to trigger it programmatically including these discussion posts and the documentation, but couldn’t figure it out. This is my Luasnip config

local ls = require("luasnip")
local s = ls.snippet
local t = ls.text_node
local i = ls.insert_node
local fmt = require("luasnip.extras.fmt").fmt
ls.add_snippets("all", {
  s({trig = "````", name = "Codeblock"}, fmt([[
    ````{}
    $TM_SELECTED_TEXT
    ````
    ]], {
      i(1)
  })),
  s({trig = "sspan", name = "Custom Span"}, fmt("<span style=\"{}\">{}</span>", {
      i(1), i(2)
  })),
})

I tried this but it doesn’t seem to work: vim.keymap.set({ 'n' }, "<leader>r", function () require('luasnip').snip_expand("Codeblock") end). I get this error (home folder name omitted):

E5108: Error executing lua: .../.local/share/nvim/lazy/LuaSnip/lua/luasnip/init.lua:230: attempt to call method 'copy' (a nil
value)
stack traceback:
        .../.local/share/nvim/lazy/LuaSnip/lua/luasnip/init.lua:230: in function 'snip_expand'
        /Users/../.config/nvim/init.lua:318: in function </Users/.../.config/nvim/init.lua:318>