We would like to buy a subsciption for a client

Question

We need to buy licenses for a project.

Is it Legal to buy on our tanant and use it in a client project?

Where can we read more information about the licenses options?

https://portal.azure.com/#view/Microsoft_Azure_Marketplace/GalleryItemDetailsBladeNopdl/preview/undefined/id/portnox.portnox-clear-aut18/resourceGroupId//resourceGroupLocation//dontDiscardJourney~/false/_provisioningContext~/%7B%22initialValues%22%3A%7B%22subscriptionIds%22%3A%5B%5D%2C%22resourceGroupNames%22%3A%5B%5D%2C%22locationNames%22%3A%5B%5D%7D%2C%22telemetryId%22%3A%22e8bc1aed-9cab-456a-8a4d-12f6d608600a%22%2C%22marketplaceItem%22%3A%7B%22categoryIds%22%3A%5B%5D%2C%22id%22%3A%22Microsoft.Portal%22%2C%22itemDisplayName%22%3A%22NoMarketplace%22%2C%22products%22%3A%5B%5D%2C%22version%22%3A%22%22%2C%22productsWithNoPricing%22%3A%5B%5D%2C%22publisherDisplayName%22%3A%22Microsoft.Portal%22%2C%22deploymentName%22%3A%22NoMarketplace%22%2C%22launchingContext%22%3A%7B%22telemetryId%22%3A%22e8bc1aed-9cab-456a-8a4d-12f6d608600a%22%2C%22source%22%3A%5B%5D%2C%22galleryItemId%22%3A%22%22%7D%2C%22deploymentTemplateFileUris%22%3A%7B%7D%2C%22uiMetadata%22%3Anull%7D%7D