How to register a new effects ?

How to register a new effects ?
I do not see any possibility to register new effects plug-ins dll . Is there a chance?

See here for VST plug-ins:
Audacity Manual .

If it is a LADSPA plug-in for Windows (DLL), just put it in the “Plug-Ins” folder inside the Audacity installation folder then restart Audacity.

If you do not see the new plug-ins, Edit > Preferences: Effects and make sure “LADSPA” and “VST” are checked under “Enable Effects”, click OK and restart Audacity.