Meltan is not normally obtainable in Cobblemon unless a specific addon, datapack, or server plugin adds it
Check whether your Cobblemon version includes a Meltan addon or custom spawn configuration
If using a server, ask the server staff whether Meltan is enabled and where it can be found
If using a modpack, look for any included Pokémon expansion addons that add Meltan
If the mod/addon supports it, obtain Meltan through its configured spawn method, special item, or event
If no addon is installed, Meltan cannot be caught in standard Cobblemon gameplay
Use the modpack or server documentation to confirm the exact method for your setup