JSON error while sending test mail

Hello. I had asked this again two days ago. I have set up MailPoet but I cannot send test mail and receive the following error:

Request error not JSON:
<b>Notice</b>: Undefined index: path in <…> on line <b>217</b>
{“result”:{“result”:false},”msgs”:{“error”:[“\u062e\u0637\u0627\u06cc\u06cc \u0631\u062e \u062f\u0627\u062f. \u0646\u0645\u0627\u06cc\u0634 \u062c\u0632\u0626\u06cc\u0627\u062a \u0628\u06cc\u0634\u062a\u0631<\/a>”],”xdetailed-errors”:[“\u062e\u0637\u0627\u06cc \u062

I tried the solutions provided in previous treads but none of them worked. Please help

https://ww.wp.xz.cn/plugins/wysija-newsletters/