Please explain to me why it use に instead of をin these sentences

• 彼に会います ー　彼に連絡します is that because aimasu is transitive verbs? please tell me more detailed. thankyou

Please explain to me why に is used instead of を in these sentences

彼に会います
彼に連絡します

Is that because 会います is a transitive verb? Please give me more detail.