If you want to add the logotype in your Turnkey application, just upload your logotype through portal.mdriven.net or MDriven Designer. You should name your file "logo" and use .png or .svg extensions. The logo is placed in the _AssetsTK\SiteAssets folder.

Also, you can add a favicon to your application. You should upload a favicon in 16x16 pixels size and with .png or .ico extension.

It seems like we must use .ico files to show up as a favicon. If you only have a png. consider a conversion from here: https://convertico.com/