Congress was able to finesse the call for an Amendments Convention for the direct election of senators because some states had language in their petitions stating that if Congress sent such an amendment to the states for ratification, then their petitions for a convention should be considered discharged. Enough states had such language in their petitions that the threshold went below the two-thirds line. Therefore, Congress said an Amendments Convention was no longer required by law.
This is the "put a gun to the head of Congress approach", and it worked in 1913. The other alternative is to follow 90% of the procedures in that download file and actually have an Amendments Convention with its purview delineated by the state legislatures. So there are two ways to put the gun in the hands of the states.