It's helpful for internal teammates who don't have access to Linear to be able to file bug reports so we created a Google Form that folks can fill out with their bug reports. The form has some basic fields (see image below).
When users submit the form it adds it to a Google Spreadsheet where the google-app-script.js file is added as a script (to add this go to the spreadsheet, click "Tools" > "Script editor"). From there it uploads all the screenshots to Linear and creates a Linear issue with the submitted info.
To get this to work for you, you'll need to update any of the text in angle brackets in google-apps-scipts.js (like <LINEAR_KEY>). Good luck!