Indiana State Representative Ethan Manning (R-Denver) has introduced HB 1134. It would require some statewide candidates nominated by minor qualified parties to submit a petition of 4,500 signatures, with at least 500 from each U.S. House district. See it here. The details are not spelled out.
The bill makes no theoretical sense. Candidates of parties that have primaries must submit such petitions, but the purpose of those petitions is to keep primary ballots from being crowded. But that rationale doesn’t apply to parties that nominate by convention.
The only party that nominates by convention in Indiana is the Libertarian Party.