@astrojuanlu @mattkram @joss It is a lot of work and time that is needed to get in the indexes.
Technically they could (see the referenced paper below).
They have a #DOI and #crossref, which seems to be sufficient.
Fun fact: They wrote in PeerJ about their first year (https://pubmed.ncbi.nlm.nih.gov/32704456/), which is available via PubMed.