No. When applying for a UK ETA, the most important information is the applicant’s own passport details, personal information, contact details, face photo, payment information, and other required details.
Companion information is generally not a required item for UK ETA approval.
However, even if you travel with family, friends, or colleagues, each traveler must have their own UK ETA under their own name.
Babies and children are not exceptions, and one person’s UK ETA cannot be used for other companions.
Therefore, if you are traveling with others, each person should apply for a UK ETA separately and check that everyone has been approved before departure.