Uploading Javascript File Upload To Supplementary Files for theme configuration


I am novice to Telligent, I have question related to javascript file upload for Theme configuration on Telligent 8.5 

I  would like to use the .js file to be added to theme but for this we need to upload .js file to the Supplementary Files. Unfortunately .JS file extension upload is not supported and we get an error that the only file types that are supported are  .jpg, . jpeg, .png, .ttf, .otf, .eot, .css, .svg, .woff, .ico, less. 

Can you please suggest how to reference a .js file at theme level and where the .js extension file can be uploaded if not under supplementary files. 

Thank you & Regards,