I got some details from the silver wheaton website regarding the sreaming deal. I hope this information is wrong and doesn't apply to Silvercorp metals.
Stream Details
Date of Contract 17-Jan-22
Term Life of Mine
Stream 50% gold until 150,000 ounces, then 33% and 75% silver until 4.6 million ounces, then 50%
Upfront Consideration $175.5M
Per Unit Production Payment 18% of spot until upfront deposit repaid, 22% of spot thereafter