can I using import without annotating the script to be type=’module’

Actually, I am using a non-module javascript files
I have installed creditor and I want to use Base64UploadAdapter from ckeditor
the official documentation tells me to use

import Base64UploadAdapter from "@ckeditor/ckeditor5-upload";
i

nside my js
but when I use this, it will say that

SyntaxError: Unexpected identifier ‘Base64UploadAdapter’. import call expects one or two arguments.

when I change the script to

<script src='test.js' type='module'>

I have to set some functions from test.js to export function

for example:

export function test() {
   alert('this is testing');
}

but I have used directly test() from other many many js files already,
if I change to export
I have to add

import { test } from 'test.js'

before using test function

I wonder how can I fix this problem? Thanks!!

I have tried following the instruction from official ckeditor5