You do not need to add a variant in order to have a multilingual sitemap. You are thinking of an older standard where you needed to have different sitemaps for different language domains. That's not the case with this module, as it produses one sitemap that includes links to all language variants.
If you still want the older standard, you can either use xmlsitemap, or alter the sitmap generation process as described in this issue.
Angebot innerhalb von 24 Stunden
Ob ein großes kommerzielles System, oder eine kleine Business Seite, wir schicken ein Angebot ab innerhalb von 24 Stunden nachdem Sie diese Taste drücken: Angebot anfordern
You do not need to add a variant in order to have a multilingual sitemap. You are thinking of an older standard where you needed to have different sitemaps for different language domains. That's not the case with this module, as it produses one sitemap that includes links to all language variants.
If you still want the older standard, you can either use xmlsitemap, or alter the sitmap generation process as described in this issue.