Desert where they travel, having received German approval (6)
I believe the answer is:
mojave
'desert' is the definition.
(I know that Mojave is a desert)
'travel having received german approval' is the wordplay.
'travel' becomes 'move' (synonyms).
'having received' is an insertion indicator.
'german approval' becomes 'ja' ('yes' in German).
'move' placed around 'ja' is 'MOJAVE'.
'where they' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Another definition for mojave that I've seen is " S. California desert".)