When paying & getting paid digital currency invoices, there is a difference to be made between invoice currencies and payment currencies.
Invoice currencies are the currency you choose to issue the invoice in during creation, mainly based on what is required to be compliant following your local tax & accounting laws.
As an example: In the United States of America it is required to denominate any invoice that you have issued and/or paid in the United States Dollar (USD) for bookkeeping/accounting purposes. Payments can be made in a different currency.
Payment currencies are the currency that you end up receiving when issuing an invoice, or spend when you're on the recipient side of an invoice. These can be traditional currencies like EUR, USD or GBP which you receive on your bank account, or digital currencies (cryptos) like ETH, BTC or DAI which you receive on your digital wallet.