cURL Error:35:Unknown SSL protocol error in connection to fcm.googleapis.com:443

[bushibigniu]

When I use php7.2 to call the sendNotification method for web push, a lot of Curl Error: 35: Unknown SSL protocol error in connection to fcm.googleapis.com:443 will appear, why is this. I use a loop to push. Will there be a frequency limit for this api? Does this version require an SSL certificate？

my code: $webPush = new WebPush($auth); $res = $webPush->sendNotification( $subscription, $playLoad, false );

lib version: "minishlink/web-push": "^5.2.0" php version: ^7.2 system: centos 7