Spanish residents abroad: Who will they vote for?

Spanish citizens living abroad can vote in elections. Some parties, like Vox, want to stop this voting. They say it is not secure and difficult to manage.
The Spanish government allows around 2.7 million citizens living abroad to vote. These voters use the Absent Voters Census (CERA) to register. Vox believes that allowing mail-in voting is a problem. They want all expats to vote in person at Spanish consulates. This issue has been discussed for many years, including a similar situation in Galicia twenty years ago.
Summarized from the sources above. Read the originals for the full story.
Highlights
Millions Vote Abroad
Spanish citizens living abroad vote in each election.
Vox Wants Halt to Mail Voting
Vox asks the Central Electoral Board to stop mail voting for Spaniards abroad.
2.7 Million Registered Voters
Currently, 2.7 million citizens are on the Absent Voters Census.
Concerns About Voter Data
Political parties question the data of voters abroad.
Galicia Incident Impacts Leaders
A 20-year-old incident in Galicia affected Sánchez and Feijóo's strategies.