525 Error when making API Call over worker

export async function translateHtml(htmlContent, sourceLang, targetLang, env) {
    try {
        console.log('Translating HTML content...');
        console.log(htmlContent);
        const authKey = getEnvironmentVariable('DEEPL_API_KEY', env);

        const response = await fetch('https://api-free.deepl.com/v2/translate', {
            method: 'POST',
            headers: {
                'Content-Type': 'application/x-www-form-urlencoded',
            },
            body: new URLSearchParams({
                auth_key: authKey,
                text: htmlContent,
                source_lang: sourceLang.toUpperCase(),
                target_lang: targetLang.toUpperCase(),
                tag_handling: 'xml', // Ensure HTML/XML tags are preserved
            }),
        });

        // Check if the response is successful
        if (!response.ok) {
            const errorText = await response.text();
            console.error(

);
            throw new Error(

);
        }

        const result = await response.json();
        return result.translations[0].text;
    } catch (error) {
        console.error('Error during translation:', error.message || error);
        throw error;
    }
}