Hello @Ersaa_Mamdouh_Hisham. I guess you are not using the compound from the tutorial here: https://training.galaxyproject.org/training-material/topics/computational-chemistry/tutorials/cheminformatics/tutorial.html?
If not, it may be that the chembl database simply doesn’t have any compounds which are similar to yours.
If you already have a list of SMILES for docking (or just 1), you can upload the file to Galaxy and continue with the next step.