Dev builds will not have a reliable plugin release.
#### Install the plugin "From File"
Once you have downloaded the `i2pfirefox.su3` file, open [`http://127.0.0.1:7657/configplugins`](http://127.0.0.1:7657/configplugins) and scroll to the bottom of the page.
Under the heading **Installation from File**, click the "Browse" button.
In the window that appears, select the `i2pfirefox.su3` file you just downloaded.
Finally, click the "Install plugin from File" button.