The resources link for this credit directs us to use the ETo software calculator from the FAO website:

Previously I have used the WaterSense website to get ETo data, but after pressing the "go" button, the data does not pop up anymore:

In lieu of the software, would it be acceptable to use this source to gain ETo data? After entering the latitude and longitude of your site, the ETo is provided with fewer steps than the software. It looks like it uses the Penman-Monteith equation like the above software does, but without the ample technical jargon.

Are there any concerns with using the IWMI to get ETo data to satisfy this credit?