SQL Server 2019

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select *
into t
from (values (98765, 'agent1
agent2
agent3')) v(ticket, agent)
1 rows affected

select *
from t


ticket
agent


98765
agent1
agent2
agent3


select t.ticket, s.value as agent
from t cross apply
     string_split(t.agent, '
') s
order by s.value;


ticket
agent


98765
agent1

98765
agent2

98765
agent3