If a single EU importer's total net weight of all controlled goods imported in one calendar year does not exceed 50 tons, they are exempt from CBAM obligations (Regulation Annex VII). Note that this threshold is based on the buyer's total volume, not what you sell to them—if the buyer also purchases controlled goods from other suppliers, they can easily exceed the threshold.
Complete information and tariff code list: https://patisco.com/zh/eu-check/cbam Search by tariff code to find which new EU regulations apply to you: https://patisco.com/zh/eu-check