The one dollar coin denomination (written as $1) was introduced in Australia in 1984, replacing the earlier banknotes. The original reverse design by Stuart Devlin on circulating coins has not been changed since its introduction. The denomination is also often used to issue circulating commemorative coins with various reverses.
The denomination is also used by both the Royal Australian Mint and the Perth Mint to issue an extensive range of collector coins which are legal tender in Australia but are not intended for circulation - such as this one. The coin is larger than the normal $1 coins.
2019 Australian Citizenship $1 Coin in Card | The Perth Mint
The Mint says about this coin:
This coin is part of the Perth Mint Australian Citizenship series which is issued every year.
The Mint says about it:
"Designed for new citizens, this legal tender coin in aptly themed packaging is an expression of pride and happiness for all those who choose to make Australia home.
The journey to becoming an Australian culminates at an official Citizenship ceremony where migrants make the Australian citizenship pledge. A proud moment in any new citizen’s life, it is often marked by family and friends with a personal memento recognising their embracement of Australian customs and culture." | 
Search for Australia: One Dollar 2019 Australian Citizenship on eBay 
