Welcome to Microsoft Q&A forum and thanks for using Azure services.
As I understand, you are getting error in Elastic Database after creation of Index Fragmentation Stored Procedure.
Please check below links if helpful for your usecase:
Ola Hallengren’s SQL Server Maintenance Solution – Index and statistics maintenance
Could not find stored procedure in SQL Server
SQL Server Index and Statistics Maintenance
Let us know if this is helpful else please share more details so that we can assist you further.
Thanks.