From their Booth: https://rbnz.booth.pm/

Also, recently Pixiv Booth had rejected my card for some reason, so I unfortunately won't be able to obtain new materials for a while.

I still have many more of this artist's work to share, but it won't be long before I run out.

If you know any method of fixing this issue or getting around it, please let me know.

I have never encountered such a situation

It is uncertain whether the following methods are effective:

Maybe other payment methods can be used：https://booth.pm/payment

Maybe you can use the purchasing website

Base +6

如果没有伤到脑子核心区，是会有正常生理反应的

Base +5