There is no issue and no difficulty. Just rock up to the network shop of your choice, activate an eSIM with them, top up your account with the required amount(perhaps 200 baht) and then tap in the USSD code on your phone's keypad to apply the package of your choice. Currently, 200 baht gets you unlimited data at up to 15 Mbps with unlimited voice calls. Just top up by 200 baht prior to the renewal date 30 days later if you want to continue with the package.
The network is up to you.
You can choose a monthly package using my method or buy a long term pack from DTAC as illustrated by BaanOz.