Please read the following articles for easy understanding

1.

The text addition attack can be performed by using any image editing software that facilitates adding text over images.

Please clear your question. There are two ways to add text in the image.

1- Type of doodle. As suggested by @Musheer Ahmad.

2- ASCII converted text embedding in some pixels of the image. This can be done by altering some pixels' bits with respect to ASCII bits.

In case of fragile watermarking, both should be reported by the scheme.