I would personally recommend you remove your background before uploading it to WordPress. (Therefore not using a plugin)

Depending on how complex your image is and your technical knowledge, I would suggest downloading a free trial of Photoshop and to use a YouTube tutorial on how to remove a background (There are some really good ones out there)

If you want to pursue the plugin route. If you can’t find that plugin when searching inside WP, you can download it from the repo and upload it inside WordPress. However, Magic Edge – lite hasn’t been updated in over 3 years so could have some technical issues.

Hope that helps.