2 sec search turned up these: https://www.aliexpress.com/item/2PCS-Soshine-18350-battery-1000mAh-3-7V-Li-ion-Rechargeable-Battery-with-battery-protective-storage-box/32810204209.html?spm=2114.search0104.3.2.65c8275dRIJpOl&ws_ab_test=searchweb0_0,searchweb201602_4_10065_10068_10130_10890_5730315_10547_319_10546_317_10548_10545_10696_453_10084_454_10083_10618_5729215_10307_538_537_536_10059_10884_10887_100031_321_322_10103,searchweb201603_6,ppcSwitch_0&algo_expid=45f891d8-5673-4f50-9a41-e96945a8f164-0&algo_pvid=45f891d8-5673-4f50-9a41-e96945a8f164&transAbTest=ae803_3
Dunno bout Soshine but other cells I thought were ok. Cheap w/free shipping, least for the US. I see buyers of these from all over the world.