That exam is "non-proctored", which means you can be anywhere with an internet connection when you attempt it. You cannot take it at a testing centre.
You get a 48-hour window in which to take it from when you book it, hence the dates of April 16th-18th being displayed to you.
It shows in the "Online Exams" section of the Pearson VUE site, all those exams are non-proctored:
And when you try and book it: