Read up on synth levels versus line level. The Eurorack signal is a LOT hotter than line level.
How you handle it is up to you and depends a lot on your gear. There are line level mixers and audio interfaces that can handle synth level without distorting. But there's no guarantee that everything will.
There are quite a few choices when it comes to interfacing.
You can buy a Eurorack interface like the Expert Sleepers ES-8.
You can buy a Eurorack module that converts synth level to line level.
You can buy an external mixer that has enough headroom at the input level to handle Eurorack.
You can attenuate the signal in Eurorack going out to your audio interface.I use a synth to line level Eurorack module. I find that to be the easiest solution without the worries.
The biggest issue is going the other way around: line level to synth level. That requires boosting the signal and has to be done with active electronics. Using a non-specific piece of Eurorack to boost the signal can add lots of noise.
-- Ronin1973
Thanks for the reply! i added a external out for the simplicity of things.