The SELCO Libraries App is no longer functional. It was developed by a third-party vendor who stopped supporting it and shut off access to it. A replacement app is in the works, but it may be several months before it is ready to roll out.
In the meantime, SELCO has put together a cheat sheet you can access by using the following link:

https://docs.google.com/document/d/1JUL9zKCMelfcuT7ZyHeYggDAADDbdtE48Vp9C_hc29U/edit#heading=h.ssf1cjnrfqel

Or go to the following link on a computer:

https://selco.ent.sirsi.net/client/en_US/ler/