Ckbutton is not visible on Ionic 4

Ionic Framework ionic-v3
1

Hi i am working on an Ionic 4 project. I am using CKEditor. I add a custom ckbutton. It is not visible though. My code is as follows:

<ckeditor style="color:red" [config]="ckeConfig"
[(ngModel)]="mycontent" name="myckeditor"
id="myckeditor" required debounce="500" 
#myckeditor="ngModel" [readonly]="false">
            
<ckbutton style="color: red;" [name]="'saveButton'"
[command]="'saveCmd'" [toolbar]="'styles,1'"     
(click)="save($event)" [label]="'Save Document'"></ckbutton> </ckeditor>

and inside ngOnInit method:
this.ckeConfig = {
height: 400,
allowedContent: false,
extraPlugins: ‘divarea’,
forcePasteAsPlainText: true,
toolbarGroups: [{
“name”: “basicstyles”,
“items”:“saveButton”,
“groups”: [“basicstyles”,“saveButton”],}],
toolbar:
[{ name: ‘basicstyles’,items: [‘Bold’, ‘Italic’,‘saveButton’] }]};

I was wondering, if you could help me ,please?
Thank you in advanced.