package grub-efi-amd64-signed 1.173.4+2.04-1ubuntu47.5 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1

[grosorg]

Dell XPS 13 9310 - failed to update and upgrade.
Error message was found without steps how to proceed with that. (Or single click of a button "Yes, please. Fix that")

One of the last messages: Your system has UEFI Secure Boot enabled in firmware, and the following kernels present on your system are unsigned:
5.15.49-051549-generic

These kernels cannot be verified under Secure Boot. To ensure your system remains bootable, GRUB will not be upgraded on your disk until these kernels are removed or replaced with signed kernels.
 - but how I can do that?

ProblemType: Package
DistroRelease: Ubuntu 20.04
Package: grub-efi-amd64-signed 1.173.4+2.04-1ubuntu47.5
ProcVersionSignature: Ubuntu 5.14.0-1054.61-oem 5.14.21
Uname: Linux 5.14.0-1054-oem x86_64
ApportVersion: 2.20.11-0ubuntu27.25
Architecture: amd64
CasperMD5CheckResult: skip
Date: Tue Jan 24 17:39:41 2023
DistributionChannelDescriptor:
 # This is the distribution channel descriptor for the OEM CDs
 # For more information see http://wiki.ubuntu.com/DistributionChannelDescriptor
 canonical-oem-somerville-focal-amd64-20200502-85
ErrorMessage: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
InstallationDate: Installed on 2022-03-24 (306 days ago)
InstallationMedia: Ubuntu 20.04 "Focal" - Build amd64 LIVE Binary 20200502-05:58
Python3Details: /usr/bin/python3.8, Python 3.8.10, python3-minimal, 3.8.2-0ubuntu2
PythonDetails: N/A
RelatedPackageVersions:
 dpkg 1.19.7ubuntu3.2
 apt 2.0.9
SourcePackage: grub2-signed
Title: package grub-efi-amd64-signed 1.173.4+2.04-1ubuntu47.5 failed to install/upgrade: installed grub-efi-amd64-signed package post-installation script subprocess returned error exit status 1
UpgradeStatus: No upgrade log present (probably fresh install)