You can change your plan only once in a month but I changed from Subscription to Pay-Per-Traffic at this time. Please check and choose again your item. https://mudfish.net/docs/en/policy/data_plans.html#how-to-change

thanks my friend, i have a problem with lost ark, when i try to download in slove, the download never start you know why? it's my vpn or stove the problem?

As workaround you should use one of methods at Unsupported Games. And if you want to see it officially at Mudfish, please send me some game packets using Packet Capture with Mudfish link while playing the game with Full VPN mode.