You are the only one sending transactions, so you don't need to call
StarkEx processes transactions sequentially, based on the value of each transaction's id, so the ids in your list of transactions must include all integers in the range of values.
For example, for a list of three transactions, the list of transaction id values cannot be
0,1,3, it must be
0,1,2. It can also be non-sequential, such as
0,2,1. If the list doesn't include an integer, StarkEx stops processing when it reaches the missing id and waits for it to be submitted.