Sending an Email on Form Submission

Hi
I got a API key below from sendGrid.
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
I wrote codes below for “sending an Email on form submission”. It look like it is worked because I saw: " message:“success”", but I couldn’t find any Email in the recipient. Any problem in following code ? Thank you in advance.