When i look at the configuration (YAML) of my working ESP-devices i found out that api: and ota: does not contain any value:
# Enable Home Assistant API
api:
ota:
why is it that way and why do they work anyhow without this settings?
Both just need to be there to be enabled. And while both have an optional password, i never seen ota without a password, but that can be down on how you installed ESPHome? Either way for ota i would suggest using a password or anyone can fiddle with your esp devices 
So, what could i have done to miss this feature? Is there a switch burried somewhere in the configs?
Can i check/do this afterwards?