Error SEOPRESS

Hello,
I have this error crashing my website when editing a booking.
Below this error there is the content of the line 113
If you could enlighten me about this ?
First time a see this one.

=======
Fatal error: Uncaught Error: Undefined class constant ‘MAJOR_VERSION’ in
/home/xxxx/wp-content/plugins/wp-
seopress/vendor/guzzlehttp/guzzle/src/Utils.php:113 Stack trace: #0
/home/xxxx/wp-content/plugins/wp-
seopress/vendor/guzzlehttp/guzzle/src/functions.php(71):GuzzleHttp|Utils::defaultUserAgent()
#1 /home/xxxx/wp-content/plugins/post-smtp/Postman/Postman-
Mail/google-api-client/vendor/guzzlehttp/guzzle/src/Client.php(194):
GuzzleHttp|default_user_agent() #2 /home /wp-
content/plugins/post-smtp/Postman/Postman-Mail/google-api-
client/vendor/guzzlehttp/guzzle/src/Client.php(75):GuzzleHttp\Client-configureDefaults(Array)
#3 /home/xxxx/wp-content/plugins/wp-
seopress/vendor/google/apiclient/src/Client.php(1210):GuzzleHttp|Client->__construct(Array)
#4 /home/xxxx/wp-content/plugins/wp-
seopress/vendor/google/apiclient/src/Client.php(1163):Google|Client-createDefaultHttpCliin
/home/xxxx/wp-content/plugins/wp-
seopress/vendor/guzzlehttp/guzzle/src/Utils.php on line 113

Une erreur critique est survenue sur ce site. Veuillez consulter la boite de réception de l’e-mail
‘administration de vote site pour plus d’informations.

En apprendre plus sur le débogage de WordPress.
=======

Line 113 below

=====

/**
     * Get the default User-Agent string to use with Guzzle.
     */
    public static function defaultUserAgent(): string
    {
        return sprintf('GuzzleHttp/%d', ClientInterface::MAJOR_VERSION);
    }

=====