Welcome to Microsoft Q&A, thank you for posting your here!!
We cannot do this with Private Link Service and Private Link Service only works with SLB however we cannot place a Storage Account behind a SLB.
So, you have to use a Private Endpoint only. Private Endpoint can make use of a Private Link Service or a PaaS service but if we already established Private Link Service won't work.
In this scenario you must have a VNET in the same subscription as the Storage Account and create a Private Endpoint in this VNET and access this PE using VNET Peering from VNETs in different tenants
Please refer the below thread:
https://stackoverflow.com/questions/65811204/cross-subscription-private-endpoint-in-azure
Hope this helps!
Kindly let us know if the above helps or you need further assistance on this issue.
Please do not forget to "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.