Did you check that you extension is successfully published.
Go to Extension Management and search for your extension.
For publishing into sanbox try adding in your launch file two more parameter, sandboxName & Tenant.
Second ally the idRanges check this :- docs.microsoft.com/.../devenv-object-ranges, seems those in not in your range.
50.000-99.999
This range is for per tenant/customer customizations. A partner can develop an extension tailored to the individual tenant to fit the needs. The partner will develop this either by using a sandbox tenant or by obtaining a Docker image of the current release of Dynamics 365 Business Central that matches the version of the tenant. Once the development is done, the extension can be deployed to the individual tenant.
1.000.000-60.000.000
This is the RSP range which partners that have an ISV solution for on-premise have access to. The partner can choose to use this range for developing extensions that can be used either in Dynamics NAV on-premise or in Dynamics 365 Business Central in the cloud. When used in Dynamics 365 Business Central these extensions are obtained as apps from appsource.microsoft.com.
70.000.000-74.999.999
Partners can obtain ranges for extension development that runs in Dynamics 365 Business Central in the cloud. This range is only available for extension development and only in Dynamics 365 Business Central. These extensions are obtained as apps from appsource.microsoft.com.