Expert Key Management

Hello everyone 

Please i need some help, i was attempting to make work my nvidia card...well was almost like a sword fight at the end...the point is that i attempted to sign the kernel with my own certificate following this official tutorial https://wiki.debian.org/SecureBoot#Disa ... t...didn´t worked for me, but i realised that when i run the command dmesg | grep cert i get a lot of certificates, the one i created named hera and anothers from Microsoft or Ubuntu as you can see:

root@hera:/home/michel# dmesg | grep cert
[ 1.244298] Loading compiled-in X.509 certificates
[ 1.267172] Loaded X.509 cert 'Debian Secure Boot CA: xxxxxxxxxxxxxxxxxx'
[ 1.267182] Loaded X.509 cert 'Debian Secure Boot Signer 2021 - linux: xxxxxxxxxxxxxxxxxx'
[ 1.268433] integrity: Loading X.509 certificate: UEFI:db
[ 1.268460] integrity: Loaded X.509 cert 'Dell Inc. UEFI DB: xxxxxxxxxxxxxxxxxx'
[ 1.268460] integrity: Loading X.509 certificate: UEFI:db
[ 1.268475] integrity: Loaded X.509 cert 'Microsoft Corporation UEFI CA 2011: xxxxxxxxxxxxxxxxxx'
[ 1.268475] integrity: Loading X.509 certificate: UEFI:db
[ 1.268487] integrity: Loaded X.509 cert 'Microsoft Windows Production PCA 2011: xxxxxxxxxxxxxxxxxx'
[ 1.269214] integrity: Loading X.509 certificate: UEFI:MokListRT (MOKvar table)
[ 1.269392] integrity: Loaded X.509 cert 'Debian Secure Boot CA: xxxxxxxxxxxxxxxxxx'
[ 1.269393] integrity: Loading X.509 certificate: UEFI:MokListRT (MOKvar table)
[ 1.269636] integrity: Loaded X.509 cert 'ubuntu Secure Boot Module Signature key: xxxxxxxxxxxxxxxxxx'
[ 1.269637] integrity: Loading X.509 certificate: UEFI:MokListRT (MOKvar table)
[ 1.269801] integrity: Loaded X.509 cert 'hera: xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
[ 7.149009] cfg80211: Loading compiled-in X.509 certificates for regulatory database
[ 7.149750] cfg80211: Loaded X.509 cert '< Private Email id removed.TOS69> xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
[ 7.154494] cfg80211: Loaded X.509 cert ' xxxxxxxxxxxxxxxxxx'
[ 7.167625] cfg80211: Loaded X.509 cert 'sforshee: xxxxxxxxxxxxxxxxxx'

Thing is...how can i delete some of them? I dont need anymore the certificates from Ubuntu or Microsoft...i just need the Microsoft and Dell certificates...but i want to delete Ubuntu, Debian and Hera (Created by me).

This can be done from the Bios secure boot option? i mean the Expert Key Managment.?????