@Ricmarug You are able to export one specific survey link so that you can send it via a different channel and use of the participant portal is not necessary. See the “Get Survey Link” option here.

The link is then something like (all placeholders replaced):
https://brandid.qualtrics.com/jfe/form/SurveyId/?Q_TS_ID=ThreeSixtyId&Q_TS_RE_PID=SubjectId&Q_TS_PID=EvaluatorId&Q_TS_RS=Self&Q_TS_TOKEN=SomeToken
Subject and evaluator IDs would be the same in this case. Retrieving those in bulk would probably be possible via API. However, the token can not be retrieved and therefore it’s not possible to put the link together on your own. Without the token, the link will not work. Therefore, you will need to use the “Get Survey Link” option one by one and can not download a full list of all self-evaluation links. I hope that your number of subjects isn’t that high so the approach works for you.
There is a feature request to download the 360 survey links in bulk.