Conflict with AIPower plugin

When both plugins (AI Power + Rank Math Google Indexing API) are active, we are unable to publish posts. Trying to publish a post results in the following error: Once the Rank Math Google Indexing API plugin is disabled, we are once again able to publish posts.

AH01071: Got error ‘PHP message: PHP Fatal error: Uncaught Error: Undefined class constant ‘MAJOR_VERSION’ in /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/gpt3-ai-content-generator-premium/lib/vendor/guzzlehttp/guzzle/src/Utils.php:116\nStack trace:\n#0 /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/gpt3-ai-content-generator-premium/lib/vendor/guzzlehttp/guzzle/src/functions.php(71): GuzzleHttp\Utils::defaultUserAgent()\n#1 /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/google-indexing-api-by-rank-math/vendor/guzzlehttp/guzzle/src/Client.php(194): GuzzleHttp\default_user_agent()\n#2 /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/google-indexing-api-by-rank-math/vendor/guzzlehttp/guzzle/src/Client.php(75): GuzzleHttp\Client->configureDefaults()\n#3 /var/www/vhosts/mywebsite.com/httpdocs/wp-content/plugins/gpt3-ai-content-generator-premium/lib/vendor/google/apiclient/src/Client.php(1213): GuzzleHttp\Client->__construct()\n#4 /var/www/vhosts/mywebsite.com/httpdocs…’, referer: https://mywebsite.com/wp-admin/post.php?post=48538&action=edit