SuikaTalk is not your employer. Instead, you operate as an independent contractor while teaching on the platform. It is your responsibility to report your earnings as self-employed income. SuikaTalk does not provide specialised tax forms for this purpose.
If you need proof of income, you can download documents from PayPal. Please note that tutors from various countries teach on SuikaTalk, and each country has its own laws regarding reporting income. You must check your country’s regulations and report your earnings accordingly.