Thank you for reaching out.
Currently, it is not possible to search by ROR identifier. We will work on this and it will be possible to do searches via the API using ROR identifiers.
You can check the progress in this related card:
In the meantime, you can do searches by GRID, Ringgold and Fundref.
I hope that this information helps. Do let me know if you have any further questions or if there's anything else that you'd like to discuss.