How to add multiple select checkboxes in google sheets

This tutorial discusses creating a multi-select checkbox from the drop-down list in google sheets.
There are many use cases where you want the people using the sheet to choose more than one value in a cell from a drop-down list, but google sheet allows you to select only one option out of the given list.
Considering you guys don't have any knowledge of HTML or javascript this tutorial is designed to make a custom script to achieve the use case without any prior knowledge.

Here is the source which can be used to copy and paste into your own script.

[NazmulBhuiyan-eihk]

Bro, it's not working for me. I am selecting the options and clicking SET but not working

[eddietreizman-az]

I liked the solution you proposed a lot...BUT...I'm getting this error when trying to follow your steps...maybe because of your selection of "Who has access":

An error occurred. Please close the dialog and try again.
Reported error:
Only users in the same domain as the script owner may deploy this script.

[divyesh.it]

Is it working fine n smoothly? I want to add it to my googlesheet

[JatinBansal-bxii]

Still not working for me, when I am clicking on Set, the values are not getting set
I don't know how others are able to crack this.

[drtabathaparker]

Can't get the script - can you repaste it? It is cut-off

[mahfujrisad]

no check boxes (options) are loading in the side pan