In order to search for one or more PUMA objects, you need to give a regular expression, along with a number of character mismatches that you will tolerate. For example, if you try
regular expression: phosphofructkinase mismatches: 1
You need to also be aware that the search is often against text that contains synonyms of objects, so you may see an object that apparently should not have been selected by the pattern that you gave (this is particularly true of pathways, which often have a number of alternative names).
Here you should type a regular expression.
The following is an optional "number of allowed mismatches".