“The truth of the temporary, I made the decision, I reached 100% about a month ago.
Swansea host Oxford United in the final match of the tournament, which will be the last game of Alen’s last career.
“I have had the opportunity to think and take it all inside. I am really happily waiting for my last game on Saturday,” he said.
“I’m very proud, I didn’t think I’m sitting here by playing some games that both for the clubs I’ve played at that level and for Wales.
“I have been unbelievable and as I have thought in recent weeks it is very grateful to all those who have helped me to have these amazing experiences.
Allen’s resignation appears to be a disappointment for Welsh manager Cyg-Blam, who was born to the international retirement after claiming responsibility for last year.
Allen initially suspended his job in Wales in February 2023 after the 2022 World Cup.
Wales have ended 64 years waiting for the World Cup in Qatar, but the tournament was disappointed for Robert Page as they left the group stage.
Allen kicked off in the tournament’s final against England after returning from the second leg against Iran in the long run.
There was a better time at Euro 2020, when Wales reached the second round, and it was all memories in the 2016 European Championship.