External links to other Spreadsheets in Onlyoffice

According to Onlyoffice they added ability to add external links to other spreadsheets in [ 7.3](https://forum.onlyoffice.com/t/onlyoffice-docs-v7-3-released-enhanced-forms-and-security-smartart-watch-window-and-more/3754)

https://helpcenter.onlyoffice.com/ONLYOFFICE-Editors/ONLYOFFICE-Spreadsheet-Editor/UsageInstructions/AddExternalLinks.aspx

I try to test this feature in oCIS running using this guide
https://owncloud.dev/ocis/deployment/ocis_wopi/

But unfortunatelly this feature doesn't seem to work. (tried with default docker-compose which uses onlyoffice 7.3.3 and latest onlyoffice image from dockerhub)
According to Onlyoffice helpcenter: "Note: in the online editor, the ability to insert data via an external link must also be implemented on the integrator side (e.g., in a third-party document management system)."

I'm not sure that i'm doing everything right, but if i do and support from the oCIS needs to be implemented -
I believe this feature is a blocker for a lot of organizations and users to move to Onlyoffice and oCIS from smth like Google Spreadsheets with their IMPORTRANGE.

Maybe this could help a bit
https://api.onlyoffice.com/editors/insertingexternaldata