Plomosas ADVANCED EXPLORATION Sinaloa, Mexico OPERATOR GR Silver Mining ("GR Silver") COMMODITY TYPE TERMS LAND AREA Silver, Gold, Royalty 2.0% NSR 6,547.54 ha Lead, Zinc Royalty Summary Reserves Plomosas is a permitted, advanced exploration stage silver project in Reserves & Resources - Zn Sinaloa, Mexico owned and operated by GR Silver. After assuming P&P Reserves (mlbs Zn) - ownership of the project, GR Silver announced an updated resource M&I Resources (mlbs Zn) 126 Inferred Resources (mlbs Zn) 183 estimate at the Plomosas project and began an in昀椀ll drill program to add new zones into the resource model. Reserves & Resources - Pb P&P Reserves (mlbs Pb) - As reported by GR Silver, Signi昀椀cant results from the in昀椀ll drilling pro- M&I Resources (mlbs Pb) 104 gram at Plomosas include 518 g/t AgEq over 44.5 meters, 1,146 g/t Inferred Resources (mlbs Pb) 132 AgEq over 12.5 meters and 471 g/t AgEq over 24.9 meters. Reserves & Resources - Ag P&P Reserves (koz Ag) - GR Silver recently began test mining and bulk sampling at Plomosas M&I Resources (koz Ag) 8,804 where an initial extraction of 2,100 tonnes of material was processed Inferred Resources (koz Ag) 8,509 yielding 26 tonnes of concentrate at 12,715 g/t Silver, 12.85 g/t gold Metalla Royalty Ounces - GEOs and 6.9% lead. P&P Reserves (koz) - M&I Resources (koz) 6.7 Metalla holds a 2% NSR royalty on Plomosas, subject to a 1% buy Inferred Resources (koz) 7.6 back for $1 million. • For royalty ounce calculation, Metalla estimates 100% of the Plomosas and San Juan Mineral Resources and Mineral Reserves are subject to our royalty interest and the zinc and lead Royalty GEOs factor in a 15% NSR smelting charge. Zinc has been converted to Royalty GEOs assuming $1.10 per pound. Lead has been converted to Royalty GEOs assuming $1.00 per/oz. Silver has been converted to Royalty GEOs assuming $23.00/oz. • For sources, please refer to note 19 on the Notes & Sources page. Royalty & Mineralization Map Royalty Boundary Metalla Royalty & Streaming Ltd. 33