Get in-memory OLTP index usage

SELECT OBJECT_NAME(i.[object_id]) AS [Object Name]
	,i.index_id
	,i.[name] AS [Index Name]
	,i.[type_desc]
	,xis.scans_started
	,xis.scans_retries
	,xis.rows_touched
	,xis.rows_returned
FROM sys.dm_db_xtp_index_stats AS xis WITH (NOLOCK)
INNER JOIN sys.indexes AS i WITH (NOLOCK) ON i.[object_id] = xis.[object_id]
	AND i.index_id = xis.index_id
ORDER BY OBJECT_NAME(i.[object_id])
OPTION (RECOMPILE);

sys.dm_db_xtp_index_stats (Transact-SQL) – SQL Server | Microsoft Docs

Get any memory dumps from SQL Server

Get Memory Clerk Usage

Check Memory pressure on the server

Memory Grants Pending value

Resource Governor Resource Pool information