lovelybrittney on "[Plugin: WP Mail SMTP] 405 error not allowed after sending test email"

I used the settings indicated for gmail smtp but I get this error every time I try to send a test: 405 Not Allowed
nginx/1.8.1 Can someone help me with this?

My website is here: Body By Brittney

Thank you!

https://wordpress.org/plugins/wp-mail-smtp/