collective answers - anonymous participants

Hello,
I have a similar situation https://www.qualtrics.com/community/discussion/1872/collective-answers, except I will not have the participants' IDs in advance. We have a long survey where we believe in some cases, a person will not have all the information we are seeking and will want to share with a colleague - e.g. a person from HR will answer some questions, a person from Finance some others and a person from Supply chain another set (block) of questions. But we are going to distribute anonymously. I was hoping participants can share a link to an incomplete survey - in a way one can return to an incomplete survey and continue where they left off. But not sure if/how they can generate a link to an incomplete survey (from anonymous distribution). Is this possible or do we need to send personalized links?
Alternatively, I understand we could perhaps utilize a retake option if we setup action as described here: https://www.qualtrics.com/support/survey-platform/data-and-analysis-module/retake-survey-link/
Sharing an incomplete survey and submitting once complete is our preferred option.
Many thanks in advance.
Sarka