How to make automatic increment by 1?

Question

Angular

When adding new data, I always have 0 displayed at the beginning of the ID, but how to make it take a number from the database and add +1 to each new entry:
sprBitType.ts:

<code>export class SprBitType{
    constructor(
        public bit_type_id: number,
        public name: string,
        public is_active: boolean,
        public rn: number) { }
}</code>

Component.ts:

...
    sprBitTypes: Array<SprBitType>;
    isNewRecord: boolean;
    private isOpenForm: boolean = false;
constructor (
private serv: SprBitTypeService, 
public toastManager: ToastsManager,
)
    {this.sprBitTypes = new Array<SprBitType>();}
...    
        createPost() {
            this.isOpenForm = true;
            this.sprBitType = new SprBitType(0,"",false,0);
            this.sprBitTypes.unshift(this.sprBitType);
            this.isNewRecord = true;
        }
...

    saveSprBitType() {
        this.isOpenForm = false;
        if (this.isNewRecord) {

            // Добавление запись

            this.serv.createSprBitType(this.sprBitType).subscribe(data => {
                this.toastManager.success('Данные успешно сохранены!', 'Выполнено'),
                this.loadSprBitTypes();
            });
        
            this.isNewRecord = false;
            this.sprBitType = null;
        
        } else {
            
            // Изменение запись
           
            this.serv.updateSprBitType(this.sprBitType).subscribe(data => {
                this.toastManager.success('Данные успешно сохранены!', 'Выполнено'),
                this.loadSprBitTypes();
            });
            
        this.sprBitType = null;
        }
    }
...