I have Mabook air I cannot add Brother Genuine ink printer too. Have tried everytthing

The Brother HL-L2305W is an Apple AirPrint-enabled printer. No cables are required. Add it as an AirPrint printer. When asked how it is to be added to Printers & Scanners, you must specify AirPrint.

In no particular order, reboot your router, the printer, and your Macs.

Needless to say, if you are using any non-Apple "anti-virus" products or so-called "firewalls", don't. A lot of things won't work if you do.

What is that printer's exact model designation please? For example, Brother MFC-L2730DW is an exact printer model designation.

For reference: Add a printer to your printer list so you can use it on Mac - Apple Support.

It could have failed.

As requested above, Brother printer model? They have myriad.

Is this a new printer, or one you have not previously used?

If this printer supports AirPrint (as many do), does it work from any other iPhone or iPad devices?

Have you chatted with Brother?

Here is how to get to the wireless printer configuration web interface menus, without installing any add-on apps:

https://support.brother.com/g/s/id/htmldoc/printer/cv_hll2300d/uke/index.html?c=us_ot&lang=en&prod=hll2305w_us#GUID-38AF46DB-3219-46C6-A242-A0F83ED4B229_109

You will need the printer IP address, which is usually available on the front panel or from printing a printer setup page, depending on the printer.

Here is how to print out the network setup, which includes the IP address (for the above web interface):

https://support.brother.com/g/s/id/htmldoc/printer/cv_hll2300d/uke/index.html?c=us_ot&lang=en&prod=hll2305w_us#GUID-44BEFA90-16C6-48A6-8A51-4A2D1A14D01F_141

Here are the passwords:

https://download.brother.com/welcome/doc101074/cv_eng_login_password_insertion_a.pdf

Here is how to use AirPrint with this and similar Brother printers:

https://download.brother.com/welcome/doc100128/cv_hll2340dw_eng_ap_i.pdf