@shashank There are no migration steps for SSRS from SP2013 to SP2019, as SSRS in SP 2019 not exist at all. The way you can use is to migrate to PowerBI, which in most cases mean you have to rewrite reports using PowerBI. Which all you:
1st - making your report better and more usable to clients
2nd - reduce the number of reports (as users will be able to drill-in-to existing reports
3rd - manage distribution (sharing) reports much more effectively than with SSRS
Links which could help:
- Get more from your data with analytics solutions | https://www.microsoft.com/en-gb/resilience/business-insights-analytics-solutions?ef_id=83653195475414e0084051bff0df75fa:G:s&OCID=AID2100620_SEM_83653195475414e0084051bff0df75fa:G:s&msclkid=83653195475414e0084051bff0df75fa
- Migrate SQL Server Reporting Services reports to Power BI | https://learn.microsoft.com/en-us/power-bi/guidance/migrate-ssrs-reports-to-power-bi