Aquamirae is a Minecraft: Java Edition mod distributed for Java mod loaders such as NeoForge, Forge, Fabric and Quilt. A Java mod JAR or source archive is not a Bedrock add-on and should not be installed as one.
Why Bedrock searches cause confusion
Aquamirae is published as a Minecraft: Java Edition mod for Java mod loaders. A Java JAR or source ZIP is not a Bedrock add-on package, so moving it into a Bedrock device or behavior-pack folder will not convert it into a compatible edition.
Why Java and Bedrock packages are different
Java Edition mod loaders execute Java mod packages and depend on a Java-specific modding ecosystem. Bedrock Edition uses a different add-on system, file structure and runtime, so the packages are not interchangeable.
Do not rename a Java file to make it work
Changing a file extension or archive name does not convert a Java mod into a Bedrock add-on. If a page claims otherwise, treat that claim cautiously and verify the actual platform support.
What “Minecraft 1.21.1” means here
On this site, 1.21.1 guidance refers to Minecraft: Java Edition because that is the version line used by Aquamirae’s Java mod releases.
Safe next step for Bedrock players
If you play Bedrock Edition, do not install the Java files described here. Use only content specifically packaged and documented for Bedrock by its own creator.