Functions - Go build error (no required module provides package)

Hey everyone!

So I am playing around with serverless functions and Go but as soon as I add a module from Github the build.sh script fails. Here is a minimal example:

package main

import (
  "net/http"

  "github.com/digitalocean/godo"
)

type Request struct {
  Token   string `json:"token"`
}

type Response struct {
  StatusCode int    `json:"statusCode,omitempty"`
  Body       string `json:"body,ommitempty"`
}


func Main(in Request) (*Response, error) {

  client := godo.NewFromToke(in.Token)

  return &Response{
    StatusCode: http.StatusOK,
    Body:       "Yay!",
  }, nil
}

The error when executing doctl serverless deploy <folder> is

Deploying '/user/sample/test'
  to namespace '...'
  on host '...'
Submitted action 'test' for remote building and deployment in runtime go:default (id: ...)
Transcript of remote build session for 'test':
Output of failed build in /tmp/slices/builds/.../sample_test/2022-07-23T22-30-16.224Z/packages/sample/test
initializing modules
go: creating new go.mod: module exec
go: to add module requirements and sums:
        go mod tidy
building
test.go:6:2: no required module provides package github.com/digitalocean/godo; to add it:
        go get github.com/digitalocean/godo


Failures:
Error: While deploying action 'sample/test': './build.sh' exited with code 1

Does anyone have an idea what I am doing wrong? Thanks a lot for the help I really appreciate it :)