You can send messages like this even after being blocked on WhatsApp, here are some easy tips and tricks:

Sometimes it happens, when we are not wrong and our partner or friend blocks us on WhatsApp. If your friend or family member has also blocked you, then do not worry at all, because here we are going to tell you two such ways, with the help of which you will be able to send messages to the blocked user easily. So what's the delay, let's know...
delete account and recreate

Details:-

Open your whatsapp
go to setting
Here you will get the option to delete the account, click on it
Now enter your phone number and click on delete my account again
Doing this will delete your WhatsApp account
Create account by reinstalling WhatsApp
Now you will be able to send message to the user who blocked you on WhatsApp
Note: For your information, let us tell you that if you delete your WhatsApp account, then you will be out of all WhatsApp group. You have to request the group admin to rejoin the group.
Send message by creating personal WhatsApp group

To send a message to the blocked user, you create a WhatsApp group with the help of you and his friend or any family member.
Also add the user who blocked you to this group
Once a group is created, your common friend or family member will leave that group
Now you will be the user in the WhatsApp group, in which you have been blocked.
Working on this feature

Here you will be able to talk to the blocked user

In a screenshot shared by WABetaInfo, WhatsApp is working on a feature that will introduce a camera button in a user's business settings. By clicking on it, users can select a photo or take a new photo to use as the cover photo for their profile. Along with this, WhatsApp users will be able to put profile cover image like Facebook.