Go to scholar.google.com and select the hamburger menu (three short parallel lines) in the upper left:
Then select Settings, and then select Library links and do a search for Washington State University and select all options (except the ones for WSU campuses other than your own if you see any ;-) Note that I have also selected Open WorldCat; this will offer you the chance to move from the freely available Open WorldCat to the WSU Libraries WorldCat Discovery catalog (this is a great resource for locating books not available in Search It or via Summit and is linked in the Libraries Search It catalog). Open WorldCat should be there by default, but if it is not just search and add the links for the WSU Libraries, then do another search for Open WorldCat and add it then.
While you are on the Settings page, why not change your Search Results settings to show 20 results instead of the default ten. Also, if you click on the Account link you will see a checked option for "Signed-in off-campus access links." This is provided by Google Scholar, not the WSU Libraries, and basically remembers your WSU log-on credentials in certain circumstances even if you are off-campus.
Every so often you may need to re-do these settings if you are not seeing the FindIt@WSU button in your results (sometimes a browser update or history/cookies flush erases your settings) - note also that if you flush your cookies automatically your setting won't be saved. Also note that the Find It @ WSU button will not show up for every result.