I'd be happy to help you troubleshoot the issue with installing MEGAsync on Ubuntu 22.04.

Firstly, it seems that you have already tried installing some necessary libraries (libicu-dev, libicu48, and libicu48-dbg) but still couldn't solve the problem.

To install the current MEGAsync desktop client on Ubuntu 22.04, you can follow these steps:

1. Open a terminal window on your Ubuntu system.

2. Add the Mega's repository to your system by running the following command:

```

sudo add-apt-repository ppa:megasync/ppa

```

3. Update your package list by running:

```

sudo apt-get update

```

4. Install MEGAsync using the following command:

```

sudo apt-get install megasync

```

If you encounter any issues during installation, you can try to troubleshoot it by checking the output of the command or looking for error messages in the system logs.

Additionally, if you're still experiencing problems, you may want to consider checking the MEGAsync documentation and community forums for more information on troubleshooting and resolving common issues.

Also, please note that the current version available through this repository is 4.11.0, which seems to be a different version from the one mentioned in your key ('MEGAsync 4.6.1').

For iphone instal MEGAsync 4.11