As noted in many of the comments, the Duolingo sentence is using incorrect English grammar. We do not use the present perfect tense in a past tense situation. It is unfortunate that it has not been corrected yet after two years, but keep in mind that it is a free program, and the contributors are volunteers. Possibly, as ddookisland points out, a word simply got omitted in the printing process. It has not rained since yesterday.