Fast-indexing-issue

WordPress version 5.9
Current theme: Divi (version 4.14.7)
Current Addition: Instant Indexing (Version 1.1.6)
PHP version 7.4.27

Error details
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An E_ERROR error occurred due to line 218 in the file /home/elabnoudy/public_html/wp-content/plugins/fast-indexing-api/vendor/firebase/php-jwt/src/JWT.php. Error message: Uncaught DomainException: OpenSSL unable to sign data in /home/elabnoudy/public_html/wp-content/plugins/fast-indexing-api/vendor/firebase/php-jwt/src/JWT.php:218
Stack trace:
#0 /home/elabnoudy/public_html/wp-content/plugins/fast-indexing-api/vendor/firebase/php-jwt/src/JWT.php(186): FirebaseJWTJWT::sign(‘eyJ0eXAiOiJKV1Q. ..’, ‘—–BEGIN PRIV…’, ‘RS256’)
#1 /home/elabnoudy/public_html/wp-content/plugins/fast-indexing-api/vendor/google/auth/src/OAuth2.php(1394): FirebaseJWTJWT::encode(Array, ‘– —BEGIN PRIV…’, ‘RS256’, NULL)
#2 /home/elabnoudy/public_html/wp-content/plugins/fast-indexing-api/vendor/google/auth/src/OAuth2.php(460): GoogleAuthOAuth2->jwtEncode(Array, ‘– —BEGIN PRIV…’, ‘RS256’, NULL)
#3 /home/elabnoudy/public_html/wp-content/plugins/fast-indexing-api/vendor/google/auth/src/OAuth2.php(494): GoogleAuthOAuth2->toJwt()
#4 /home/elabnoudy/public_html/wp-content/plugins/fast-indexing-api/vendor/google/auth/src/OAuth2.php(534): GoogleAuthOAuth2->generateCredentialsRequest()