This is the 17925th most frequent Russian word.
участнику
"To the participant."
Here, 'участнику' is the dative case singular of 'участник', referring to a participant receiving something (indicated by 'предоставили').
Каждому участнику конференции предоставили материалы.
Each participant of the conference was provided with materials.
In this example, 'участнику' is used to denote the recipient of the award, showcasing the dative case as well.
Учитель вручил медаль лучшему участнику соревнования.
The teacher awarded a medal to the best participant of the competition.
Although here 'участникам' is the plural dative case, it exemplifies the connection between action and recipients.