Ignition Designer two different version install in the same pc?

I install Ignition Version 8.1.24 in my PC ;

I install Ignition Version 8.3.6 in my Docker as testing ;

How to install two different version Designer?

When I download Designer in Version 8.3.6, next install jump to the same old install folder, can't let user select ?

The launcher is not the designer. The designer must match the gateway to which it connects, and the launcher facilitates that. The v8.3.x launchers can do this for v8.1 gateways as well.