For SPF, use this (leave the name field blank, use this as value):
"v=spf1 include:tommy.heliohost.org ~all"
For DMARC, enter the name as _dmarc, and use this value:
"v=DMARC1; p=quarantine"
For DKIM, the record needs to be generated in Plesk under the mail settings as its unique to each user. Turn it on, apply the settings, then click the ? next to the DKIM settings and it will show you the correct records to use.