How to copy a BBBike map into Basecamp?

Do you mean a map or a route or track?

If a map you can't simply do it. If a route or track as a .gpx file you just use File, Import 

If it's a map or not a .gpx file please explain what it is in more detail.

Thanks for your answer.

This is the situation: I downloaded a map from the BBBike site (part of France). In the download it has an .img extension. I just want to transfer the map from the download file into Basecamp. I don't see a Basecamp option to do this.

By the way: I know how to transfer the file directly to my GPS bike unit (a Garmin). But I want to transport it first to Basecamp on my Mac.

You can't install a .img file for BaseCamp to use although you can read it off your device or a removeable drive, eg a sd card, memory stick or virtual drive. For help with that see https://www.javawa.nl/virtualdevice.html

You could also check the BBBike website as many map providers also offer installation options for your computer.

Thanks a lot Sussamb for your help. It's all clear.