It works well with the connector. Be aware, however, that it also works without it, but it can lead to a kind of loose contact. This is the case with me. Specifically, this means:
If I'm not quite "at the edge" with the screech on the colour palette in the app, the main strip and the extension strip don't light up in the same colour because of this wiggle contact at the connection point.

You either plug the extensions together directly or use the connectors. There is one for each extension - why more? ;) These can be bent, so they can also be placed around corners, but they are quite short (approx. 6-8 cm).