Where have you looked?
What do you search for?
What have you tried?
Where is the code you are using and detail / show what errors you are having.
You cannot ‘export’ tags or other descriptive info, you can only report on them.
MS provides guidance and resources for one to do this sort of use case.
There are several blogs posts similar to what you are after, even pre-built script in such posts.
Using a search string like
‘report on azure vm tag info’
Script Sample - Generate Azure Resources Report by Tags
PowerShell for Assigning and Querying Tags in Azure
Even scrips on the MS PowerShellGallery.com
Azure ARM Detailed VM Inventory with Tags
Sample script to export detailed Azure ARM VM with Tags The output creates 1 file per subscription and allows filtering by Key tag values. Support up to 15 tags key per subscription.
Download : AzureARMVMinventorywithTags.ps1