If your deposit is not credited yet, and you would like to contact Dedprz support team to help you with that, you should first find your transaction hash since they will surely ask for it.
You can find it in your wallet history (external wallet, from which you sent the funds).
Just go to your transaction history, find the transaction to stake, and you should be able to open it in some of the crypto explorers and find your transaction hash.
Transaction hash is a string of numbers and letters, and it should look something like this:
93423d92ddbe2f823fcae746c9fade7bce35f69ae42e5f15449375ac4e0fdb78
Or it can be in the form of a link from the crypto explorer