Adobe InDesign allows export of its own markup language documents (.idml) up to Encapsulated PostScript file format (.eps), which is what idml to eps conversion actually represents. To do that Select File menu ► Save As.. and select the EPS format. Fill the name box and click on Save button, which will produce an .eps variant of your file.
As far as we know, no 3rd party app can process IDML format, so using inDesign remains your only option.Open IDML file Open EPS file
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