Most of these posts come from people that have no idea what they are talking about
IT DEPENDS
If they own the Trademark IN THE SAME CLASS AS YOUR PRODUCT
AND
They registered their trademark BEFORE you registered your domain
Then "you copied them" and you cannot use their trademark
HOWEVER
If you registered your domain name and THEN THEY REGISTERED THEIR TRADEMARK
you are "grandfathered in" and you are free to use that domain for whatever you wish
providing that you DO NOT PRETEND TO BE THEM OR INFRINGE ON THEIR TRADEMARK
OF THAT CLASS.
Ask a trademark lawyer on one of their free consultations
Trademark 2019 : legal care for your business & product name
https://welib.org/md5/07ef60d638e13215827562dacc33dcca
Patent, Copyright & Trademark: An Intellectual Property Desk Reference, 17th Edition
https://welib.org/md5/d917b8ff83041ca1ba2adfe1bc50ddb0
Sincerely,
The Eye