K3b I haen't the permission to burn cd in bionic beaver

K3b doesn’t burn cds because I haven’t the permission for cdrecord.
I have read same topics but i can,t resolve the problem; isn’t impossible to operate in k3b settings.
K3b worked perfectly on 17.1 Could you help me?
thank you very much.
this is the message:
Devices

hp DVDRAM GU70N U703 (/dev/sr0, CD-R, CD-RW, CD-ROM, DVD-ROM, DVD-R, DVD-RW, DVD-R DL, DVD+R, DVD+RW, DVD+R DL) [DVD-ROM, DVD-R Sequential, DVD-R Dual Layer Sequential, DVD-R Dual Layer Jump, DVD-RAM, DVD-RW Restricted Overwrite, DVD-RW Sequential, DVD+RW, DVD+R, DVD+R Dual Layer, CD-ROM, CD-R, CD-RW] [SAO, TAO, RAW, SAO/R96R, RAW/R16, RAW/R96P, RAW/R96R, Restricted Overwrite, Layer Jump] [%7]

System

K3b Version: 17.12.3
KDE Version: 5.44.0
Qt Version: 5.9.5
Kernel: 4.15.0-21-generic

Used versions

cdrecord: 1.1.11

cdrecord

/usr/bin/wodim: Operation not permitted. Warning: Cannot raise RLIMIT_MEMLOCK limits.
/usr/bin/wodim: Resource temporarily unavailable. Cannot get mmap for 12587008 Bytes on /dev/zero.
Text len: 450
TOC Type: 0 = CD-DA

cdrecord command:

/usr/bin/wodim -v gracetime=2 dev=/dev/sr0 speed=10 -sao driveropts=burnfree textfile=/tmp/k3b.rx3112 -useinfo -audio /tmp/k3b_audio_0_01.inf /tmp/k3b_audio_0_02.inf /tmp/k3b_audio_0_03.inf /tmp/k3b_audio_0_04.inf /tmp/k3b_audio_0_05.inf /tmp/k3b_audio_0_06.inf /tmp/k3b_audio_0_07.inf /tmp/k3b_audio_0_08.inf /tmp/k3b_audio_0_09.inf

I’ve moved this to the https://community.ubuntu.com/c/support-help-requests category because this site isn’t designed to take tech support questions. Sorry. I’d recommend using one of the official support channels listed on the https://community.ubuntu.com/t/finding-help/712 page