USB adapter for Brother MFC-J995DW with 2024 iMac?

Instead of USB, use the control panel on the Brother to join it to your Wi-Fi network. Then, visit System Settings > Printers & Scanners and see if the printer shows up there. If not, download the driver from the Brother website (https://support.brother.com/g/b/downloadtop.aspx?c=us&lang=en&prod=mfcj995dw_us).

If you have a specific reason to use the device wired, you can purchase a conversion cable that goes from USB-B to USB-C connector (https://www.startech.com/en-us/cables/usb-c?filter_cabusbconn=usb-c%2520to%2520usb-b)

Your Brother printer supports AirPrint - as does your Mac Computer. Unless you have explicit need to do so, you don't need to use wired USB connection with your printer. AirPrint is a driverless printing protocol used by Apple devices.

Start here:

Connect an AirPrint printer to a Wi-Fi network - Apple Support

Print wirelessly from your Mac to your printer - Apple Support

I thought that I would add one more possible solution to the others provided. Your iMac has an Ethernet port and others have pointed out that the Brother does as well. If you are not currently using the Ethernet port on your iMac (i.e. using Wi-Fi instead), you could try using a standard Ethernet cable to connect the Brother and the iMac's Ethernet ports, and then wait a minute for the magic. Although an often forgotten capability, most modern devices have the ability to create an auto-configured TCP/IP network between two devices connected this way. Your Brother and iMac then have their own private network that they can communicate via AirPrint.

Brother recommends using AirPrint:

https://support.brother.com/g/b/downloadlist.aspx?c=us&lang=en&prod=mfcj995dw_us&os=10088

It may also be a good idea to check whether the latest printer firmware is installed.

Please note the difference between AirPrint and wireless printing in general. AirPrint works with wireless or wired network connections. The MFC-J995DW model is equipped with an Ethernet port, so you could alternatively wire the printer to one of the LAN ports of a Wi-Fi router, if you so wish.

Or if the printer can be located near the router, use a patch cable to connect the printer directly into the RJ45 sockets available on most routers.

LotusPilot wrote:

Your Brother printer supports AirPrint - as does your Mac Computer. Unless you have explicit need to do so, you don't need to use wired USB connection with your printer. AirPrint is a driverless printing protocol used by Apple devices.

Some printers support AirPrint over USB. The Canon printer I'm using now is an example. It has no separately-provided drivers that are compatible with Sequoia, and isn't connected to my Wi-Fi network (though it could be). The only reason it still works is because of the use of AirPrint protocol running over USB.